I came back from a two week course in Krakow recently at Prolog Language school I did learn some stuff during my two weeks but some of the other students I spoke with had been at the school for 4 weeks. I found it pretty tough with all the words and grammar everyday but I feel I benifited from being in Poland
I've ask various mates who can speak a second language and they told me it took them 2 months to get a reasonable understanding of the language they were studing. However, those 2 months were spent in that country.
I have to agree with you my learning has slowed since I arrived back in the UK