Don't believe Windguru always. Also for Cabarete they sometimes don't predict any wind and we have great wind. April is normally a good month for wind. Not always the same windforce, but if you bring a few sizes, you will have a great time here. And Cabarete is a great place to be with lots of things to see and do, good nightlife, great restaurants, relaxed people, etc.
If you want more info, just send me an e-mail (we live here): firstname.lastname@example.org