I have been through about 4 trailers due to a growing rig. Two things I have learned, keep the bearings packed (learned that the hard way) and don't buy anything with Luan sidewalls. I punched so many holes in the luan sidewalls it looked like swiss cheese. 3/8' Sidewalls are the way to go for audio gear.
My Pace American 8x20 is tough as nails. It has a 6" double I-beam frame, which is stronger than the cheaper tube frames. I busted a tube frame at the weld joint before.
BTW the bearing buddies AKA EZ lube axles still need to be pulled out and have the grease removed and re-packed once every 18 months or so. The Dexter axel and EZ lube manual that came with my trailer mentioned this.