Need to see what the changed text is. It could be the old one where it shows a value of 45K.

There is absolutely no information from Marriott to support this claim.
So far all we have is certificates members redeemed for a specific category with specific expirations. Stating that for example cat 5 will no longer be valid at cat 5 will violate that agreement.
Other stuff that was done informally like extension or upgrading/downgrading can definitely be dropped...

we had a recent example when chase IHG card tried to unilaterally reduce annual cert category but within a month backed down and reconfirmed all existing cards/certs as per original agreement

Agreed that the old cat 6 is not the same as the new cat 6, but in the old structure, to upgrade is 30K more per category (except between Tier 1/2 and Tier 3/4). In the new structure, it will cost us between 60-180K to move up just one category. My example was if one had an old cat 6 and then decided they wanted a new cat 6. In the old structure, it would have cost that person 30K. In the new structure, it is more.

I cannot speak for OssianBlue, but when I referenced these, I was speaking about hotel categories, not travel packages.

Yes, because the categories are compressed. That doesn't mean the actual cost in points is higher.

You mean, other than the recategorization of every single property in the Marriott and Starwood portfolios into the new structure?

The codes and wording on the changed certificates in my account and the emails I received after making the changes are identical to the ones I previously received after changing categories. If you are referring to the difference in the description of an unchanged package and a changed one, the language and coding would be different. The initial travel packages have "T" codes and the hotel partial packages have "P" codes. The initial Cat 1-5 travel package might have a code of T830. If the hotel portion is changed to a Category 6, the new code description will look something like: P870 Partial Package-CAT 6 - 75000 Points. I could have missed something, so please let me know if I am mistaken.

That is an excellent point. So, a new category 6 might be a category 9 now if I am correct (please correct me if not), so to move from cat 6 to 9 in the old structure is 90K. If Marriott did convert as we are discussing, their old cat 6 certificate would put a person somewhere between a new cat 4 and 5. That means they need to move up somewhere between one and two categories to get to a new cat 6. To move up from category 4 to 5 in the new structure is 60K points, so if Marriott mapped it to 5, then these people are ahead. To move up from category 4 to 6 in the new structure is 180K points which means these people take a hit.

This was the one property that I thought about booking but ultimately decided not to. It was the difference between paying 540K for two Cat 1-5 TPs at the 120K mile marker vs the 390K for that package and I ultimately went with the two TPs. No regrets because I still value the airline miles more than the room points but it looks like an incredible property.

Yes and no. Some of it is due to Cat compression, but more-so from using 6 night peak pricing as the basis plus the 1.5:1 airline transfer ratio. At lower Cats its pretty close:

A clean example would be OC5->OC7, which have the same 'standard' night prices as NC4->NC5. Upgrades price assuming difference in cert cost: old = 60k (330k-270k), new = 60k (390k-330k).

But at higher Cats it falls apart.

Another clean example would be OC7->OCT3, which would have the same standard nights prices as NC5->NC7. Upgrades price assuming difference in cert cost: old = 90k (420k-330k), new = 180k (570k-390k).

VFW has quoted an update as:

"While we plan on sharing the full conversion chart on 8/18, I can let you know that all existing certificates will convert to similarly valued categories after that date. I realize you might have more questions and we will be able to answer those soon.

As I previously wrote, we encourage members who know their travel plans to make reservations prior to August 18th. For members that are not sure of their future plans, please be advised that you will not be able to modify your certificate for an existing reservation or attach it to a new one between August 18 and September 18, 2018."

If true, that is good about getting the update on the 18th and it appears that they are thinking 'cats' and not 'points' if I interpret it correctly, which makes sense as I have previously attempted to articulated with how hotels are being distributed (for instance 98% of OC9 45k/night hotels are going to NC6 50k/night hotels and above). If they are going to announce on the 18th, hopefully they are being conservative with the 1 month blackout and can get things functional again sooner.

Now back to the original debate about round up/down of old cats 6, 8, 9, which was interrupted by the points refund Lurker comments. Hopefully they don't look at peak night prices when determining 'similar value', as that could be pretty bad (old RCT5->NC7 or OC8->NC5).

And the final question would be, for those who were 'rounded down' would they be refunded, perhaps the old Cat downgrade equivalent.

We do 7 day vacations as a standard: leave for long-distance travel on Th/Fr, arrive Sat, stay 7 days, return and be at work Monday. Great way to avoid blowing more than 5 vacation days but getting a great trip. We now work for ourselves but 7 days still works for staying on top of our companies.

Places where 7 days was either perfect or actually not enough time: Amsterdam, Paris, Seoul, Maui.
Places we plan on staying for 7 days next year: Munich, Thailand resort TBD, and an Australian city TBD.

I am holding a cat 1-5, but I have not decided where to use it. What is the general guess whether I will be able to upgrade the certificate by paying more points after Sep 18?

I definitely think you can upgrade by paying more points after Sep 18. I just think it will be converted to a new certificate and then you upgrade from cat 4 to whatever cat you want based on their new travel package pricing structure.

When we were in Taipei we stayed at the Grand Sheraton, which was actually pretty nice. The morning breakfast buffet was really outstanding. However, I've heard great things about the Courtyard Taipei too. I'm glad you're providing another rousing endorsement of the property. We will definitely put it high on our list for our next visit to Taipei.