I've used one for several years on a semi-auto .308 with zero problems except for a poorly-made on/off switch. The switch knob is plastic & there is a small, thin pin, designed to stop over-rotation. The pin wears rapidly but if you replace it with a small roll pin it's good for ever.
Mine is the flat button cell (CR2325)version & I've had no battery-related issues. The batterys are availiable all over the internet & Radio Shack usually has them in stock.
I like the chevron/dot retiucule because I find it easier to "pick up" the style than just a dot. Incidentally if you zero for 100yds with the dot then the tip of the chevron is good for 200yds using a .308 load.
I had no problems with the adjustments, but you do need to understand the process fully before starting & the manual isn't really clear. What you do is set the zero, with the turrets centered. Then slacken off the turrets a hair, re set them to zero & use the finger knobs to make minor changes from there on in. They say they use this dual adjustment system to allow for "wide variation in the side rail fittings" Odd as my version is for a top rail, not a side one. You absolutely needthe "special tool" which comes with the kit, but never use it to unscrew the battery compatment cover. The O-ring seal is very tight & you'll burr up the coilo slot immediately. Use a quarter instead.