CHOOSING A CROSSBOW
Picking out a crossbow is just like picking out a vertical bow. If you can, go to a proshop or sporting goods store that has a wide variety of crossbow to choose from. Then start picking them up and bringing them to your shoulder. Find one that feels right! Next step is to take it to the range and shoot it. When you finally do choose one and buy it, take it home and practice often. This part of the process will help you become one with your bow and that is extremely important.
Just about any crossbow that you buy from any of the major manufacturers will be a quality choice. They vary according to price, which is dictated by poundage, components and accessories, but start out with one that feels comfortable to you. The more natural it feels the more confident you will feel and the better you will shoot with it.
As far as poundage is concerned, ask your self this: How far do I want to walk to pick up the arrow after it has passed through the deer? A 150 pound bow will easily do that. I have found that the heavier draw weights, as with vertical bows, are less forgiving and lead to higher wear and tear on your equipment. And for those longer practice sessions, cocking 150 pounds will go a lot easier on the shooter than a 175 or 200 pounder.
Bottom line is: Find the crossbow that feels the most natural in your hands and that has good balance for YOU. It is an investment that will last for many years so it pays to take the time to choose the right one for YOU! Of course, thats just my opinion. I could be wrong.