More reliable than most HO alts out there. I've had bad luck in the past, and see thread after thread every day on here about people's HO alts messing up. How often do you see a "my stock alt fail me" thread? Not to mention my stock alt is 160amp(320 amps for two), so anything near that size in a single HO alt will run at least $400...
Yes, three 1/0 runs for grounds, using that big 3 conductor terminal I linked to earlier, straight to bare metal frame. I've ran grounds all the way back to the front before, and it didn't make more than a .1db difference on the meter than a solid ground to my frame. It's not worth the money to me to have 3 runs going back to the front.