We’ve been to Omni and liked it quite a bit. We didn’t stay in the main building though. We stayed at a condo a couple buildings down and they have all ranges of luxury, sizes, etc. We had a vehicle and often went off the grounds to eat although you could stay on Omni. It is quite spread out and huge.
IMO Omni is great with kids. There is the beach, pool, little nature center, you can rent bikes from the resort, Segweys, etc. we found plenty to keep busy.
The main hotel pool is heated but all the side condo buildings have their own pools which are not. There are tons of units that rent via Vrbo or Airbnb and most don’t have access to the main pool so keep that in mind. The main pool was fancy but also busy.
https://www.villasofameliaisland.com/~/media/aip/resort/stayhere/other/revised%20villa%20map%2011812%20small.ashx
I think we stayed in Shipwatch.
Haven’t been to ritz so I can’t comment on that.
When is your spring break? PP is right that the weather may be be reliably warm enough for pool/beach.