This topic comes up periodically and clearly sorts out to personal taste largely. I think one thing that people might agree on is, as stated upthread, the middle is tough. I personally like higher quality, preferably with a bulletproof warranty. All of my rollers are B&R. And they have honored the warranty on really old stuff that had clearly been damaged as well as stuff that had worn. I also have Red Oxx, a Tristar, SFBags, Timbuk2 and LL Bean (backpack).