Crossbow's have come a long way from the primitive weapons of old.
When I was shopping for one,I went to several archery shops and shot as many different brands/styles as I could. You'll be surprised at the difference between the different crossbows. I wanted one that was balanced,quite when fired,and still had very good speed/warranty/reputation.
The crossbow that I ended up buying was the Horton Vision 175,it had everything I wanted,and wasn't too expensive. Plus it shoots excellent!