We have stayed at many of the mentioned hotels. IMHO, Dolphin is as nice as the Disney deluxe hotels we've stayed at (BC & WL). I wouldn't consider it on the lower tier of deluxe at all, but that's personal opinion. Dolphin has full beds that don't seem that small to us. We're fine with them. Swan has queen beds, if that's a deal breaker. The one negative to this hotel is the air conditioner turns off, when you leave this room. The room becomes very humid causing the linens to feel damp. A call to the front desk will prompt maintenance to override the AC eliminating the problem. The transportation is the same as the other Epcot resorts. S/D guests are eligible for EMH. IMO, the restaurants at S/D are better than WDW restaurants, with the exception of Victoria & Alberts.
We haven't stayed at Waldorf Astoria yet, but plan to in the near future. Hilton Bonnet Creek is a very nice resort with great amenities & customer service. The only possible negative is the bus service. It is seriously lacking. Many times the bus stopped at both resorts & all 4 parks. If you just missed a bus, you could have close to 2 hrs. invested in transportation. We would stay there again, but only if we added cab fare each direction into the hotel budget. HBC/WA do not offer EMH privileges.
Calling Hilton Downtown Disney a deluxe resort is a stretch. Fortunately, we only spent two nights there. It had the worst beds I've ever slept in. Unfortunately, that's not an exaggeration. My DH said he would only consider this hotel again, after the mattresses were changed. Both of us woke up with back pain each morning. We didn't feel the customer service was up to deluxe resort standards either. On a positive note, the transportation at this resort is better than at HBC, but not as good as S/D. HDTD guests are eligible for EMH privileges. We would stay here again, if the beds were changed, & we got an incredible deal. That would be the only way. I certainly wouldn't recommend it as it is now.