We went for 2 weeks in April this year. We were warned it would be hot and very humid - and yes, it was hot and sticky, but not as bad as I was imagining. Everything was open, but the benefits were - its less crowded, so the beaches are nice and no need to book at restaurants;, the locals in the shacks / restaurants have time to chat as they aren't so busy; the sea and pools are like a bath; you get bargains when shopping "end of season prices!". I would make sure you had a place with air conditioning - we didn't and did find some of the nights unbearable at time.
I wouldn't have any problems in going in April again