I dropped down to Amb for a few months three years ago, and was disappointed by my stays during that time (the upgrades I had were mostly to 'Ambassador' floors where the rooms were the same as booked).

Although I requalified for RA this year, I'm unlikely to do so again due to changes in my work stay patterns - I could probably hit 20+ IC nights from personal spend in the next year but will struggle now to do 60 IHG nights overall. I'll do my best to get good value from my existing RA in the next 12 months though but as others have said the reports about removal of lounge access at some hotels make things less interesting.

In the UK, the choices for other schemes are fairly limited - realistically just Hilton unless you do a decent amount of international travel. I've been impressed by my recent treatment at HIs/CPs as a Plat, so will definitely hang on to that, and may try for Hilton status as well but Hyatt/Marriott/SPG don't really work for my stay pattern.