I am SPG Platinum and also Gold Passport Diamond. Which do I prefer? That is a toughie.
I like SPG in that they have many more locations throughout the world and at a wider range of price points (good for mattress runs!), which makes requalifying for elite status that much easier. As a SPG Platinum, I have generally received pretty decent treatment, with room upgrades when available and I do enjoy access to the club floor. I am disappointed that at properties where there isn't a club, that Platinums are not provided a complimentary breakfast voucher. When I am vacationing at a resort, not having to shell out $25+ each for me, the wife and youngin's for a continental breakfast sure is nice. I use to like SPG much better when they had true a true dedicated SPG Concierge, instead of the SPG Special Member Services. IMHO, Special Member Services means just a shorter wait for a service agent, but you get the same indifferent service agent as everyone else gets.
I have found that Hyatt takes very good care of their Diamonds, and what fewer properties they do have, Hyatts are generally very nice and comparable (if not nicer) than the competing SPG property. I do like that Hyatt provides Diamond benefits even if I book the room through Priceline and even allows stay credit as long as I incur incidental charges. This is a big plus. The Hyatt promotions are definitely better than SPG's recent promotions. GP's FFNs beats SPG's Free Weekends hands down. GP's Diamond Amenity is much nicer than SPG's Platinum Amenity. Even though SPG provides for 500 points as one of the Platinum Amenity choices, GP's check-in bonuses more than make up for the lack of points as an amenity choice. I just wish that GP had an afinity credit card.
I think what happened is that SPG is a large lodging provider. And as such, it may have become a bit difficult for them to consistently provide the type of service and benefits that a smaller chain is able to. Just like Hilton & Marriott, good consistent treatment, but nothing special.
SPG has been very good to me and has been pretty responsive and fair when needed. Because of a reduced travel schedule, I may have to decide which program to requalify for top status for 2005. With all the SPG points I have banked (and the increased point earning potential of the SPG AMEX), it will probably be SPG. It is hard to choose between the two programs, but needless to say I will miss being a Hyatt Diamond.