currently in Texas a crossbow can be used by any hunter during the general hunting (firearm) season. However during the archery only season, they can only be used by someone with an upper body, limb, handicap that prohibits them from using a verticle bow. Those hunters have to carry with them a doctors note re: the upper limb handicap.
They became legal for everyone during the general season a couple years back, and to my knowledge there has not been any negatives created by this.