BootsnAll Insiders

Hello,

I know the question of Spanish Immersion programs has come up quite a bit, but due to my job I have a very small window of time (mid-to-late May) to work with in terms of travel. I'm a self-taught beginning/early intermediate spanish student and have been DYING to do a Spanish Immersion. I only have a week, though, and I want to make the best of it. I'm looking for a place with warm weather and, most importantly, vibrant culture -- where is the best place to spend a week in Mid May, in your opinion? I'm in New York and money is tight, so I'd love to stay in Central America or Mexico. A friend recommended Antigua or Xela, but said that I may run into trouble since the rainy season starts right around the time I'd be going. And Antigua sounds a bit touristy. Is it too wet and cold then, do you think? Some other places I've considered:

Nicaragua (Esteli, Leon, Granada, Masatepe-Masaya, Managua, San Juan del Sur)
Mexico (Guadalajara, Marida)
Ecuador (Cuenca)
Guatemala (Antigua, Xela)

Any thoughts on what these places are like in May? And I know other posts have addressed this, but any other personal recommendations for language schools are greatly appreciated.

Gracias!
Andrea