Rolando,
I own the CM 8500 trailer (not the 8300 wagon) and I concur with Mike's opinion - get the trailer - it's way easier to back than a wagon.
Loading it unhooked from the tractor is not a problem (other than you need some counterweight for FEL work) - it has a tongue jack rated to 2000 lbs (based on the weight distribution design of the trailer the tongue weight, loaded, is far less than that) After it's loaded, just back up to it and lower the tongue jack, pin it to your hitch and off you go.
At the sale price ($800) these units are worth the money and are a pretty good deal - at the regular price I would have been sorely disappointed. The units are fairly lightly built and will not stand up to being overloaded regularly if you are hauling very heavy loads.
I have been pretty hard on mine - I estimate in the year that I have owned it I have easily hauled over 250,000 lbs. of rocks, soil, mulch and sheep manure. The sheep manure and clay was probably the worst because they were so heavy, being wet.
I've had three failures on my unit. The first was the mount for the tongue jack was inadequately welded (not enough bead) - very easy for me to fix. No problems since.
The second was that the front mount for the hydraulic cylinder tore itself off of the box tube it was welded to - the tube is only 3/16" wall thickness at most - really should be 1/4" minimum. I took a piece of 3"x3"x3/8" angle and welded the cylinder attachment point to it and then welded that to the box tube. No problems since.
The third failure was just about a week ago. After using the unit all day to move wet heavy clay, we started moving topsoil (which was alot lighter because it was drier) and the rear hinge mount broke loose on the left side when I went to dump a load. I haven't got around to fixing it because I plan to reinforce it and the weather has been too nice (rainy day project.)
If you get one these a couple of points:
1. Consider screwing a piece of plywood to the bed - it will preserve the PT lumber decking and if you coat it with oil (I used a 50/50 mix of diesel and ATF) the material will dump easier and it will stay fairly clean.
2. Make sure the unit is level side-to-side before you go to dump - otherwise it may tip over.
I can't speak to assembly of the unit other than it looks like it would be fairly easy. I picked mine up at the factory fully assembled and hauled it home in the back of a pickup. HTH.
