try and figure out a little closer what your draw length is. I wouldnt jump 10lbs like that right away! Maybe 5 or less but jumping in weight that far is going to lead to bad habits. Something you dont want to trying to fix later imo! If the bows are the same (same bow maker, same bow length, strings arra weights) the speed will be noticeably different. Being I dont have a lighter crusader (or heavier one) I couldnt tell you how much or even guess but I would bet 15-20fps. I did just see a used one on archery.net