I have one and it's a solid scope, and I mean solid in more than one way. It's held up to abuse just fine but it's a heavy pig. As for eye relief and low-light performance, I've never noticed any issues. I can check it tonight against larger scopes if you're interested.
Besides size, the main issue i have with the 2-10X Credo is the tiny FFP reticle at low power. It requires illumination to be seen. While that's never been a problem, it does annoy me. In the field, the Credo reticle becomes usable in the 4X or 5X range up to 10X. Maybe if I thought of this as a 4.5-10X variable it wouldn't annoy me. We shall see.
Last quibble: the giant Christmas tree reticle is way overkill. I wish it were just simple mil markings instead of taking up so much of the windshield at high power.
The Credo is a good scope that I trust. It works fine, has good optics, and is made by a great company. That said, would I buy one today? Nope. I prefer smaller scopes without illumination and probably SFP reticles for variable scopes.
I would trade my Credo for an SWFA fixed 6X if that says anything.