I did one of those groups for a few weeks. I just couldn't get over the fact that I was using foam. A few things bothered me but most of all it was the fact that I was using a big foam sword. The rules were also skewed. In this game, spell casters got a staff which was fine by me until i saw how deadly they are. Basically ever 'touch' was a 'hit' (even through armor) So what they basically hadwas a really long sword. I wasn't in any position to change the rules (it's thier game, it'd be rude) so I stopped going :/ Any time a wizard constantly defeats a knight in MELEE combat, something is wrong.
Running around in the forest was good exercise though.