A few weeks ago I spent a fair bit of time comparing HH and SPG at the top tier level. The impetus behind this comparison was that I was about to recommence heavy travel after 9 months without it, and decided to take the opportunity to realign my programs for maximum benefit, including changing credit cards etc. To date, I have been a HH Diamond, and United 1K. I will continue to be a top-tier traveller, and so am only comparing Diamond vs. Platinum. Since I had put so much work into it, I thought I would post it here since it would be interesting to get others comments on it, and may be a useful resource for others.

I concluded that Hilton is the best program for me, and may well be for most top-tier travellers, though it depends almost entirely on whether you earn your points through hotel stays or credit card spending (HHonors is clearly better for hotel stays, SPG is clearly better for card spending) and also on your hotel preferences.

In general, awards are 30% less expensive at HH than at SPG, if you earn your points through hotel stays.
In contrast, awards are anywhere from 10-30% less expensive at SPG if you earn your points through credit card stays.

My comparison proceeds in two parts. The first part considers the feature sets of the programs, and the second considers the reward earning rate. I should state up-front that I care mainly about the reward-earning rate, and that I only included the features I somewhat care about. There may be other features I have missed which are important to other people.....

FEATURE SET:

Breakfast - included by HH, not by SPG (adv. HH)
Award rooms always available if hotel not full - yes for SPG, yes with limitations for HH (adv. SPG)
Late check-out - yes for SPG, not for HH (adv. SPG)
Upgrade - Best available room SPG, Executive level HH (adv. SPG)
Guaranteed reservation - 72 hrs before SPG, 48 hrs before HH (adv. HH)
Health Club free - yes in both cases.
Airline points per hotel $ spent - 2.5 in both cases (but HH doesn't convert to UA)

The last feature takes a little explanation.

As a SPG Platinum with the SPG credit card I would earn 4 points per hotel $ spent (1 point per $ with the card, and 3 points per $ through the SPG program). The airline conversion ration is 1.6 SPG points for one airline point (including the bonus). So for every 4 SPG points I get 2.5 airline miles.

As an HH Diamond I earn 25 HH points per hotel $ spent (10 per $ spent, 5 for Diamond bonus, 5 for Double Dip your way, 5 with the HH Amex). The airline conversion ratio is 10 HH points per airline point. So for every 25 HH points I get 2.5 airline points.

In terms of the feature set, despite the two features in HH's favor and three in SPG's favor I view the programs as tied. This is because late check-out is hardly important to me, breakfast is, and I have not run into (and do not anticipate running into) award reservation problems because I tend to take vacations in low or shoulder seasons.

One feature that I do not take into account is the quality of hotels available for awards. My sense is that SPG has better properties in better locations, however the really good ones are AWESOMELY expensive (in award terms) compared to Hilton. I already know where we want to go for the next 3 vacations or so (Singapore/Japan/Hong Kong, then Italy, then Hawaii) and Hilton and Starwood roughly equally meet my needs, so i counted those as roughly equal.

So - the deciding issue is the reward earning rate.

REWARD EARNING RATE:

As luck would have it, both SPG and HH have 6 award categories. The categories don't actually compare properly, and so I chose the better reward earning rate in two steps.

Step one is a brute force comparison assuming the levels did compare. The thing to remember is here is that for hotel stays, HH gets 25 points per $, and SPG gets 4 points per $. For standard non-stay credit card spending, SPG gets 1 point per $, and HH gets 3 or 5 (I used 3 as my benchmark). I won't inlcude the actual calculations here, but only the results. I have the spreadsheet if anyone wants it. The following figures are the amount of cash needed to earn one award night. Here I have not taken into account discounts like VIP 6 night HH awards, and SPG 5th night free awards. I do that further below.

HOTEL SPENDING NEEDED FOR ONE AWARD NIGHT
Level 1: HH hotel spend $400; SPG spend $500-750 (depending on peak/off-peak)
Level 2: HH $800; SPG $750-1,000
Level 3: HH $1,000; SPG $1,750
Level 4: HH $1,200; SPG $2,500
Level 5: HH $1,400; SPG $3,000-4,000
Level 6: HH $1,600; SPG $5,000-6,250

As you can see, at every level, HH is better. Furthermore, spending at Level 6 for HH won't even get me Level 3 awards for SPG. If level 4 for SPG is equal to level 6 for HH, level 6 HH is way cheaper than Level 4 at SPG. Interestingly, for credit card spending the situation is (roughly) reversed....

CREDIT CARD (NON-HOTEL) SPENDING NEEDED FOR ONE AWARD NIGHT
Level 1: HH $3,333; SPG $2,000-3,000
Level 2: HH $6,667; SPG $3,000-4,000
Level 3: HH $8,333; SPG $7,000
Level 4: HH $10,000; SPG $10,000
Level 5: HH $11,667; SPG $12,000-16,000
Level 6: HH $13,333; SPG $20,000-25,000

In this case, at the lower three levels SPG is clearly better than HH. Since SPG level 4 is probably equal to HH level 6, SPG is also better for levels four and five. At level 6 I'm not sure there's any comparison, since HH doesn't have anything equal to SPG's level 6 in quality.

I think the conclusions are very clear here. If (as I do) you earn most of your hotel points through hotel stays, Hilton is clearly the program to go with. If you earn most of your hotel points through credit card spending, Starwood is (almost as clearly) better.

REWARD EARNING RATE FOR MY PLANNED VACATIONS:

As I mentioned above, since it's difficult to compare the levels at apples to apples, I went through a second round of analysis where I compared the spend needed to get acceptable hotels at our next vacation spots. In each case I assumed a 6 night stay (which biases it slightly in Hilton's favor b/c of the 6 night VIP awards whereas SPG's are 5 nights - but not enough to affect the outcome).

SINGAPORE: Level 3 hotels in both, SPG requires 29,000 points, HH 150,000 points. HH hotel spend $6,000, SPG $7,250. SPG card spend $29,000, HH $50,000.
JAPAN: Level 4 SPG hotels, level 5 HH hotels, SPG requires 42,000 points, HH 150,000 points. HH hotel spend $6,000, SPG $10,500. SPG card spend $42,000, HH spend $50,000.
HONG KONG: Level 4 SPG hotels, Level 6 HH hotels. SPG requires 42,000 points, HH 175,000 points. HH hotel spend $7,000, SPG $10,500. SPG card spend $42,000, HH $58,333.
HAWAII: Level 4 SPG hotels, Level 6 HH hotels. SPG requires 42,000 points, HH 175,000 points. HH hotel spend $7,000, SPG $10,500. SPG card spend $42,000, HH $58,333.
ITALY: Level 4 SPG hotels, Level 3 HH (for Sorrento). SPG requires 42,000 points, HH 150,000 points. HH hotel spend $6,000, SPG spend $10,500. SPG card spend $42,000, HH $50,000.

What is striking here is that for all of my planned vacation, I have to spend $3,000-4,000 more per night at SPG hotels compared to HH hotels. That is, HH is some 30% cheaper!!! Of course, if I was earning the reward vacations using credit card spending, SPG would be 10% cheaper.

METHODOLOGY COMMENTS:

As mentioned above, it is difficult to make definitive comparisons between the programs. There is certainly a ratio of credit card spending to hotel spending where the balance would tip in SPG's favor, though I suspect for anyone who spends enought to be top-tier at either program that ratio would be hard to reach. I couldn't be bothered making the calculations complex enough to include my actual spending ratio, since I know it's so heavily in favor of hotel spend.

The planned vacations sections is my attempt to deal with the problem of the top-tier hotels at SPG being incomparable to HH. The only comment I would make on those is that if you're earning only to use SPG's top hotels, bear in mind that one award week at SPG level 6 hotels gets you 3-4 weeks at HH level 6 hotels..... That's a lot of weeks to give up.....

Since I use the double-dip points plus points option, I used that. It's hard for me to see how the points+miles options is cost-effective compared to points plus points, so I didn't consider it.

Interestingly, this also suggests that Hiltons devaluation from GLON to GLON2, while a devaluation for HHonors member, was actually a realignment that kept Hilton more than competitive with SPG!!!!