The bottles are plain brown bottles perfect for entering beer in comps and the labels just float off with a long soak in hot water and oxyclean. I had a mix of bottles and after scrubbing and thumbnail scraping a few dozen Widmer bottles I learned to appreciate the Costco bottles. Soak, label falls off, any residue left behind just wipes off with no scrubbing necessary. I'm going to stop saving certain bottles and just pick up a case of Costco beer now and then to bolster my bottle supply.
I found the same thing. Hot water and Oxyclean literally melt the labels off. Most bottles like Sam Adams, New Belgium, etc. take a little effort. The Costco labels came off so cleanly I would swear they were adhered with milk.
The beers themselves aren't great, but they aren't bad. At less than $1 a piece, they will be my default when I need a case of competition-worthy bottles.