Just got back from a stay at the Marriott waterside and loved this property. Right in the heart of downtown close to convention center. On site bars and restaurants were very good and close walk to other options. Concierge lounge features a great outdoor space and one of the more attentive staffs that I have experienced - particularly Carl who huddled to make sure everyone had what they need.
I stay 100+ nights annually. If you're in Tampa for business this is a great choice.