Dropping the 4PM check out is the biggest negative for me. That was the one benefit that actually had some value. No way I would spend $12,000/year at IHG hotels and then have to negotiate a late check out up to 2PM every time. The milestone benefits are pretty good but there are just not enough properties--especially in the US that have lounges. Hopefully the breakfast amenity in lieu of points will be a step up from the nearly inedible low quality offerings at the HIX properties
Also there are an unspecified number of Kimptons that won't provide breakfast. What about waived amenity fees? Those are a huge negative for me and I try to avoid any property that charges them.
Overall, I don't see any reason to pursue Diamond--but will have the rest of the year to test it out as I use up my remaining points.