I see some nice spec illuminated AR optics from NcStar going for $60-70. Are these any good?  OK OK I'm not expecting the world here but I'd like to get a fairly nice quick detach scope for my M4.

You'll get three kinds of replies:

1) People who don't have one and will tell you to buy a $600 Leupold/Swarovski/Kahles instead.
2) People who have them and say they're OK for the money.
3) People who have them and they didn't work.

I do have one, and for light duty goofing around with, it seems to work fine. Bullets hit where I'm aiming at, within the limits of my own incompetence. Would I put it on a varmint SPR ? Probably not. But for popping the occasional coyote it's fine. If it breaks in a few years, I'm out $50.

I'm with Zhukov.  I've had one for a few months, just recently replaced it with an Aimpoint finally.  I used the carry handle Nstar 4x scope as an easy, cheap solution.  It was a son of a bitch to sight in, since it seems like each click is completely random as to how much it will change the aim point.  But, other than that, my bullets generally hit where I aimed.