This is one of the best ways we have seen for Spaniards to learn English. The daily one on one conversations enable you to get to know the Spanish and their culture very well. The work can be tiring since you are "on" all day and into the evening, but at the same time you will enjoy it. Attending the course can also be interesting as the locations are often in unusual sites. We also found that the other "anglos" were a fascinating group and that they were mature free spirits, some of whom had participated in these courses several times before.
There are often skits and group activities more designed as team building rather than learning experiences, so be prepared to have to act silly and laugh at yourself and others. It is wonderful to see the Spaniards gain confidence and improve their facility with the language.