Aluminum or steel flat deck trailer?

Okay, I'm new to this forum, not a new driver by no means, and I don't own a truck or a company. But I have a boss that does own a truck and is now thinking of replacing the old tandem 48 foot deck I pull around everyday. I haul from soup to nuts on that deck, and sometimes the weight of what ever, is a little more than what should be hauled on that old piece of boat anchor or boat dock. So now, the two of us are looking at a tri-axle highboy, oh and I live in Canada.. and yes the roads suck and so does the winter.

Question is:

What is better in the long run, an (all even the frame) aluminum trailer, or a steel frame wood deck trailer (which is my choice)
The unit I drive is paid by the hour, so getting the most amount of weight on the trailer isn't the issue. Most of what I haul is pretty light but I still get a grunt (heavy lode) once in awhile, mainly bulky stuff. It doesn't matter to me if it is a 53 foot or a 48 foot, the boss figures a 48 tri-axle aluminum, I'm thinking 53 foot tri-axle in steel with sliding axles would be nice... but he is the boss... any advice as to which is the better to own and why would be very much appreciated.

Backing up isn't an issue here, from super"B"s to quads, its doing it blind folded that scares everyone!

 

They put the soup in really big bags, kind of tricky on corners, and don't park close to anything hot unless you have another load next to you with crackers.

 

We can't run michican spreads here either, why I don't know, the tandem I'm dragging around now is about as close as you would get to a spread. And we are going with the tri-axle.

Had a talk with the boss about the aluminum frame, the ones we were looking at are all bolted together, thinking the the bolts being steel and the frame parts being aluminum, sooner or later the frame would loosen up, so I'm pretty sure we are going steel, just easyer and cheaper to fix.