Thanks for that info.

Here's how I found the Hampton MVP code being useful in a London search: I started at the MVP site, but I then added AAA, AARP, and Senior discounted rates (by clicking the checkboxes). Every hotel in London showed one of those or Member Discount except the Hampton showed MVP, and MVP was indeed lower than all of the other discounts there.

But when I repeated this for Paris (for the random date I picked), not even the Hampton showed the MVP rate as lowest.

Now, in my case, AAA, AARP, and senior rates are all valid rates for me, but even if they aren't for you, you could use this trick in searches to see which properties are really still giving MVP discounts better than most other discounts.