I had an amazing egg sandwich (the fairfax: eggs, chives, cheese, sriracha aioli on a brioche bun) here on my trip to Vegas. The service was kind of slow, but you can watch them prepare each order and they obviously take great care to make sure each sandwich is perfect. The staff was friendly as well.
I would highly recommend this spot (2nd floor or the Cosmo by the Chandelier Bar) for a late night snack or breakfast. Note: whatever you do, don't unwrap your sandwich! These babies are stuffed so full that everything will fall out if you do!