I have been going to a Dominican Stylist for years. The Spanish background in my family is of Dominican descent - so I'm partial. /images/graemlins/wink.gif
I don't know that they make the hair 'grow' so to speak - but if you find rollersets are better for your hair specifically and you don't want to have to do them yourself, a weekly visit to Dominican salon is a great way to maintain your hair in the way that's most beneficial for you without undue effort on your part. So, if your hair will stay healthier washing and setting then you'll retain more length and that will mean longer hair.
That they are "hair growing" salons is a myth. But they DO take excellent care of the hair. Some people balk at the use of high heat blowdriers to get the hair straight, but I think what some people also don't realize is that the blowdrier and brush stage of the styling process is NOT a mandatory, and not doing it makes going to these salons that much healthier an option for your hair!!! All of these salons will simply wrap the hair with pins for you if you request it after the rollers are removed. It is also possible to have the roots ONLY be straightened with heat (I do this) so that the LENGTH isn't affected by the heat of the blowdryer on a weekly basis - only the as yet unprocessed new growth is.
If you like them and the price is right, and you like the salon, I say go for it. I wash my hair 2x a week and one of them is routinely done at a Dominican salon as long as I have the money for it. /images/graemlins/smile.gif