Kydex is used in military/LE applications all over the world. It's not going to crack from paintball use. Your hip will break first, that much I can guarantee.
While I don't believe in sidearms either (I only rock a pistol as a primary), a holster can still be useful depending on what you're doing. For instance, if you're running props at a scenario, sometimes the "Evil Scenario Producer" will make them a two-handed carry deal, so having a holster to dump your pistol into is handy. Likewise if you're commanding a game, it helps to have somewhere to store your gun at the ready. Not to mention how often members of the other team will completely ignore you if you don't have a gun in your hand. You'd be surprised.
Personally I prefer soft holsters since they'll deform and compress when you bump into bunkers or go crawling through brush, but I have owned one of these low-profile Kydex ones before and they ARE very nice. Fast, smooth draw and really easy to reholster without looking down. I just don't run Tib pistols anymore so unfortunately, this is of no use to me.
Jay AKA Rogue...
Reservoir Dogs Scenario Paintball Team - Our $%^* is RIGOROUS!
Proudly and Generously Sponsored By
GOG/DLX - Valken - QuickShot Paintball - FogDoc.com - TechT - Deadlywind