The Credo (HX in my case) gives you more control over the illumination, a lot of control really, at the cost of needing a battery and potentially trouble down the road with the electronics. If that control is really important, then for me the choice is simple. After a lot of shuckin’ and jivin’, I got the 1-6, for my low-power model. Saves a good bit of weight and the difference in eye-relief between 1 and 6 is minimal, which I like. The 1-8 doesn’t give more adjustment with the big tube either. Still, I’d like to look through one someday.
The Credo 2.5-10 is a beast too. I’m still pondering where its final resting place will be. Very nice view for sure.
