I replaced my 4-leaf spings (supposedly 3000 lb springs) with 6-leaf 3300 lb rated American-made EMCO springs. The diffence in towing is very noticeable. No more wallowing through corners and, I think, no more uneven tire wear. I have noticed some evidence of stuff getting a little more jostled around in the trailer, couch may move an inch or two out from wall, etc, but nothing serious. I'm sure if I'd taken the time to reposition the shocks so that they were more effective, it would have more than compensated. I think the "hard on your camper" argument is BS.