Put the Sparc on my 10/22 last August, been out shooting with it a dozen times or so, and really like it. Clear optics, and I specifically wanted a smaller dot, so the 2MOA dot vs. the 3MOA on most others is a big plus...
It's rugged, held zero in spite of my complete lack of concern about beating up a 10/22.
Have yet to replace the battery, and it came with a spare battery in the box. We'll see how that holds out in the long term because yes, replacement batteries for these are kinda expensive and generally not available at your local corner store - or even Home Depot (which is a good place for reasonable prices on most button style batteries).
The included 2x doubler that comes with it is kinda "meh" - used it to get a good zero, then it's sat in the retail box ever since. It's clear, and no warping around the edges like a lot of add on doublers, but it narrows the field of view a lot, and it's just a carbine 10/22, so magnification to get on target past 50 yards is a bit pointless. It serves the need - a clear aim point for 50 yards and under for quick snap shooting.
I really like it.
Would I get another? I dunno. I'm going to "cheap out" and get a sub $100 red dot the next time I need one, mostly just for comparison. I mostly went with the Sparc because it has such a solid rep for reliability and quality. I was kind of experimenting with the whole concept of Red Dots, I've only ever used scopes or open sights before, so I didn't want to sour myself on the concept of Red Dots by risking getting a crappy one from the get go.