On the contrary, I think you will find most that post here recommend the immersion courses while as I am one of the few who recommend a more traditional approach. This is based on my personal experience with some immersion techiques.
The problem is that without an extensive and solid foundation on understanding how to conjugate the verbs and how to use the different articles and objects and direct object, the brain just can't figure this out on it's own (for most adults anyway).
I have met people who have studied in short term immersion courses and who apparently feel that they can speak Spanish relatively well. All I can say is that non English speaking Dominicans will say among themselves that the said people don't speak Spanish.
My personal experience is that I bought an expensive immersion course after I came to the DR on a business trip and after meeting a young lady. I had no previous experience learning Spanish but had approximately 5 years total of French. I eventually had to quit using the course, this even though I had moved to the DR a short time later to get to know the Dominican lady better. I instead bought a Spanish 101 grammer book, like one might get for the first year of college and started from there. I studied very diligently every day until I undestood many of the verbs, nouns, ido's and do's and the general method of sentance structure. With these basics I was eventually able to start to decipher what the Domincans were actually saying. However, from almost the very beginning(say 2 months of studying) I was able to communicate with a limited number of very patient people, in Spanish only of course.
I eventually married the Dominican girl and we moved back to the States for 5 years but returned 2 years ago to Santiago. My wife speaks no English nor does any of her friends, family nor many of my friends. I have a total of 8 years learning Spanish and feel I do pretty good, although I will never really be happy with it as I wish to talk like the natives. However, sometimes I get the Spanish going pretty good(especially if I don't speak a lot of English for atime) so much so that one of the fellows I was playing golf with yesterday asked me if I was Dominican. When I told them I was just a gringo these guys had fun for the rest of the round laughing at how I had become so "aplatanado".
Since I have very high standards(I wish to be fluent like the locals but never will of course even though I have good days) I recommend to most to study the old fashioned way. However, any type of Spanish course will be better than none.
take care
