Jeff,
I have the big King triple axle. It's rated to carry 12,000 and has the torsion axles and disc brakes. I had an EZ Loader prior to this with drum brakes and springs. Both we're the same gross weight trailers. I was putting new bearings (three axles worth) on the EZ every 12 to 18 months and I cared for them diligently. With the King I have had it going on four years and the last time I checked my bearings (2 months ago) they looked great. I really believe it's because of the torsion axles and the fact they carry the weight better. The disc brakes are also a wonderful improvement over drums. Last longer and easier to service. I love the King trailer and would buy nothing else at this point. Torsion is the only way to go. I probably trailer it about 4500 miles a year.