if you really have a hard time cleaning off your bcg, i can see you wantings a ni bor or chrome bcg, but srsly not worth the extra cost imho. I have a chrome bcg, looks nices but srsly would have rather spent the extra mag for it on extra mags or something.
As for a ni-bor reciever.....its all cosmetic bling. If you like the way it looks, by all means, go for it. You'll find most people will opt to forgo ni-bor coatings anywhere on your AR.
Assumption is the mother of all ****ups.
Know what you know, Know what you don't know. -Paul Pedzolt
"Jack of all trades, master of none, though oftentimes better than master of one" -Mynshul