I have hunted with a compound since i was 12 yrs old and have been shooting one since i got my "toy" bow when i was a toddler. I also have purchased a ten point crossbow 2 yrs ago. What i have found is agreeable with both sides of the issue. YES the xbow is an effective weapon out to 40 yds, however it IS loud and deer DO drop at the sound when the trigger is pulled and i WOULD NOT recommend shooting any farther than 40 yards only after much practice has been done. However the compound is just as leathal at that range and both have their negatives in the stand. Xbows are bulky and can be very hard to maneuver in the tree thus not allowing shots at all angles that i could get my compound to the get an arrow through so it is not always easy....For those that think using a crossbow is an unfair advantage you can think that but until you actually buy one and try to hunt with it i dont think you should say so. I have used one and still do in early and late season and there ARE downsides to it, it is not the cake walk most thing, the worst part about it is getting it in position of shooting lanes and finding clearance points to actually get a shot through in a stand. I however do enjoy my compound and i use that from the pre-rut on.
I do however think the biggest issue face is that like some have mentioned xbows will bring alot of idiots out of the wood work that think they are now archers. They WILL take unethical shots and WILL wound alot of deer. Also the added pressure to the woods will effect the deer activity especially in urban areas where people can go 30 yds behind their house and use an xbow to chase that big buck that comes to eat off their bushes.
I am nnot against the legalization of crossbows at all, im against the legalization of allowing idiots to go into the archery woods, but then again the same idiots are allowed out in late november with a high powered rifle.