There are many different bows out there, all of my experiences have been with Barnett, and they've treated me good.
I started off with a Barnett Wildcat.
It shot well, but was large and heavy.
Very heavy, and very large.
Now, we've been using a Barnett Recruit.
In all fairness, it is more narrow in the limbs (I think about 16 inches) and is probably a whole pound lighter than the wildcat, and the velocity is about 7 fps slower.
I use aluminum arrows, illuminated nocks, and Rage broadheads that weigh in at 467 gr. I shot one or two over the chrony and was getting around 307-310 fps with it. Of course I could gain a few fps using a carbon arrow, but I don't really like them. Seen too many horror stories online with them. So, I stick with aluminum arrows.
That's still more than enough at the distances that I hunt.
Unfortunately, I have yet to be able to take a deer with an xbow, but I hope to change that in the next week or two because season starts 9/2
One note about the Recruit. The one I have had a youth stock. I remedied that here:
http://www.mossbergowners.com/forum/index.php?threads/adding-length-to-a-barnett-youth-stock.17446/
The weight and width savings is substantial and I'm glad that I went this route.