i work at a toys r us with another guy from our boffer group. the very first day we got those nerf swords in, we were all over it. i mean, the concept alone seemed worthwhile- a professional company putting out an item that's usually more a niche market? sounds great, in theory.
after about five minutes, we came to one simple conclusion- nice kids' toys, and impressively light, but not nearly enough padding for any full-contact fighting. no functional thrusting tip, either... we actually joked about buying a few just to harvest whatever core they put into them, and rebuilding them from the ground up, but it's a bit cost-prohibitive.
interestingly, we had another pseudo-boffer item show up recently, as well. something calling itself "Mashoonga." have a look-
http://revelking.com . based off of the website and what it says on the actual toy packaging, it's like some dickwad in marketing wanted to cash in on the boffer idea, and is pretending to have invented the entire concept of beating people with a foam-padded stick. to their credit, their stuff is better padded than the nerf blades, but also are completely lacking in a functional stabbing tip. we tested; getting poked with these things isn't pleasant.
anyway, there's my thoughts. i'm not gonna claim to be definitive; i'm just an ass who happens to work at a toy store. seeing how every individual group has their own standards for what's field legal and the such, some of these things might work for you. in short, though, for the money they're asking for most these things, you could slap together about 3-4 cheap pool-noodle/pvc combos for the price of one of their prettier pieces.