I could feel a few of mine with my fingernail and still left it... Granted there were only a few like that.

 

It's a game really. Depends on what you "feel". If they are deep knicks I wouldn't personally, something barely there...who cares. It's worth giving up a couple psi of compression for the $$, hassle and time saved for tearing down your motor.

I'd still take a stock untouched OEM block for reliability with a few small knicks on the cylinder than something that was torn down and "rebuilt" leaving more room for error.