SkaerE,
I have a couple of Blade-tech straight drops and like them a lot. They offer good retention and are just about indestructable. IMO, they're harder on the finish than leather but that only matters on blued guns. For a Glock, or anything parked or stainless they're good stuff. I don't know how keen I'd be on a Kydex IWB. Seems like leather might be a tad more comfortable, though the non-porus nature of kydex may offer better protection of the gun from sweat and what not.
Unlike hielo, I like the Fobus also. It is absolutely less durable than a Blade-Tech, but seems sturdy enough. Plus, I can buy 3 of them for the price of a blade tech. I have a Fobus paddle and it has held up well so far. I think they are sturdy enough that they are unlikely to fail without some warning. If you need a paddle style holster because you'll be needing to take the gun off and put it on I'd suggest trying the Fobus. It'll at least tell you if you like paddle holsters and if it don't work your only out $20.
Even a Kydex can give you problems. I had a tension screw fall out of a $50 plus Blade-Tech, but by pure chance happened to be looking down when it fell out. The rest of that match could have been a problem if I hadn't seen that screw fall. That said, I don't think you could ever wear out a Blade-tech or other holster of similar kydex material.