I would get the one with the best mechanism (or, the one that you like best). I shoot a multi pin slider (HHA) that has the largest housing diameter I could find. I also shoot a large peep sight diameter. I can acquire a target incredibly fast. For hunting and short yardage (60 and under), I absolutely love this set-up. When I shoot TAC, I swap the housing out with a smaller diameter, single pin and put a smaller orifice in my peep. I don't find the target as fast but, it does tighten things up (especially at TAC distances). So, I guess my point is that, I wouldn't worry too much about it. As long as you have a solid mechanism, you can always swap out the housing/pin assembly.