Scott, I thought that XBows were accurate and effective at further than 50 yards.
Dave, they are accurate, but they really start dropping, and unless you've shot them a lot in the wind, you don't know what the wind will do to the arrow. You'd also have to do a lot of shooting to get them tuned in with a non-mechanical head. The mechanical heads take some kenetic energy away from the arrow to open. The cut-on-contacts don't, so they're better for longer shots, or bows with less speed.
The new compound bows surpass the crossbows for speed and accuracy in a good shooters hands. I can't shoot one offhand for nothing - if it's not on a rest I'm not shooting the x-bow. It's a different story with a rifle or a shotgun, those I can shoot offhand.
They are MUCH noisier than the vertical compound bows too. With the technology and research that has been done lately, I think the newest vertical compound bows are better than an x-bow. For sure they are a LOT quieter! For someone that can't or won't take the time to shoot on a weekly basis, the crossbow is a better hunting tool for them.
Heck, I shoot my rifles and shotguns 100's of times more than I would shoot a bow during the year.
