I used them quite a lot when I was based in Prague a couple of years ago; quite a decent operation.
If you were a member of their FF programme, it was a pretty automatic upgrade, if space was available. I think that they are in the Air France programme now.
Cabin crew generally helpful to anyone showing an interest in their country, ask them for some tips on the bars and so on. As you will know, Prague was hit by the floods last year, I'm not sure if my favourit haunts are still operating.
Everyone has chosen brews, but I always found Radegast and Krusejovice to be the best, and are widely avalable and cheap.
Have a great time!