The AMB vs RA situation reminds me of Korean Air Skypass, where there is (i) the elite tier which gives you more or less nothing useful (priority check-in, a couple of lounge coupons) for flying 30k miles every two years, and then nothing else until (ii) the elite tier which requires 500k lifetime flown miles, which is Elite Plus and gives you real benefits like lounge access. Nothing in between - no middle ground between 30k every two years and 500k lifetime total, and the former is useless. You cannot get a tier with consistent elite treatment until you've flown 500k miles. To me, that's just crazy.

They really need something in between AMB and RA to make it a compelling offering, otherwise there is just no incentive to go out of your way to direct stays to IHG if you know you won't hit RA.