I've been to Miami several times and am very particular about the hotel that I stay in; most importantly it has to be clean, close to (if not on) Ocean Drive, doesn't cost an arm and a leg, and a pool is an added bonus!
I stayed here in January with my sister and liked it so much that I'm brining my husband there before our cruise. The location is ideal, the rooms are updated and clean, and the pool upstairs isn't big but it's rooftop and you can see South Beach from your lounge chair. There is a small fitness center near the pool and there is also a facility where you can shower (if you've checked out and want to squeeze in more pool/beach time).
January isn't always super warm time of year in Miami, and if it's windy the beach maybe too chilly...which is why I like picking a hotel with a pool. The location is important because once you're near/on Ocean--you can walk to just about anywhere that you want to go. This hotel is ideal for what I'm looking for in South Beach!