I disagree with the poster who said that the Marriott late checkout is hardly any better than Hilton because it's 'subject to availability', meaning it's scarcely worth the paper it's written on. For me, the late checkout guarantee has teeth. 6 years at Plat level or higher and I've never once had 4pm request refused (half of the Plat years came from SPG though). At Hilton I can generally get 2PM without too much trouble but after that it gets considerably more tenuous. If I regard late checkout as a significant plus for a given day then I'll almost always go with Marriott.

In Europe, Marriott lounges are significantly better. In Asia, it's all good but I think Marriott has a better portfolio there; in Europe I think Hilton has the edge, especially when it comes to finding more affordable properties (and this is true the further East you go, until you get to Central Asia, which is sparse for everything).

So at least for Europe/Asia, I still put Marriott above Hilton (with the difference being wider as you move more towards FS) and have no qualms about letting my Diamond lapse this year while I continue to progress towards LTP in Bonvoy.