The downside of the ground floor premium rooms is that they can be a bit darkish as not so much light gets in and they can be shielded by some vegetation. Some people find them to feel more humid inside even (yes you can run the a/c) and others aren't keen on potential creepy crawlers entering from the vegetation surrounding each of the 3 buildings.

I never stayed in one so can't speak from personal experience. Room footprint wise, the inside areas of the rooms and suites are largely the same, the patio or balcony areas make the differences the higher you get with 4th floor having the smallest balcony areas.