Dear Evil Dog:
I have used those nocking points that you speak of, and had a problem. They cut my nice high-tech plastic finger tab. Also put a wear spot on my leather gloves. Made me mad about it!
Maybe just me, and I've not heard that problem from anyone else. And they sure get used a by a lot of shooters. Very convenient, if you have the little tool that you need. ( one more thing to buy and carry, and look for when it's needed, and it ain't there! ) Not all that easy to remove for adjustment, though. ( feels good being grumpy in the morn! )
Since it's easier to use something temporary for tuning anyway, like duct tape or masking tape, I go back to good old dental floss and glue for the permanent setup.
I've tried nocking points above, below, and on either side of the arrow nock. Seems I favor one above, so my middle finger sort of pushes the arrow up against the stopper. Two points work fine, just don't get excited when you're putting an arrow on and miss the correct spot on the string. Arrows fly real funny that way!
I guess it's mostly your preference, really.
Woodbutcher