To answer your question, the Mule tows extremely well. Honestly better than I thought. This week I was digging a bunch of french drains and moving a lot of dirt. I have a l4 wheel ATV wagon dump cart that is supposed to dump 1000 pounds. I loaded it at least 10 times (as in stacked so high the wet clay was trying to flop out) - the cart dumped it every time but strained quite a bit. Don't know what the exact load is but with the weight of the trailer I would think I easily had 1000lbs. I would take this from my yard, into the woods up a 50 yard steep hill (as in walkable but you lean way forward and sure know you are climbing it) and then to the dump area 500 yards away. never the slightest problem. My son tried doing the same with our Pioneer 500 but it couldn't make it up the hill and I had to push the trailer with the tractors bucket so he could quit spinning and get up the hill.
I also have hauled a lot with it and in Low it does great (Never tried hauling in high - figured it is not the best idea). It will never set any speed records but in low I have had logs filling the bed and stacked to the top of the headache rack (with straps to hold them in) and drive right up the hill to the house. I do this on a gravel road that is steep enough that in my pickup wants to spin going up if I don't lock it in 4x4(about ½ mile).
High will get up to about 40 on the flat, on a hill it will be less. I would say I use low 75% of the time I am using the Mule, the 25% of the time I use high I'm on the road running to neighbors or going out the lane for the mail. The factory tires are ok - not the greatest in my opinion. For working on gravel or hard pack they would be fine but I am down in the woods enough I needed stronger and gripper tires. I bought the Pitbull Growlers and been real impressed. I can leave it in tuff mode and go places I would have kicked it into 4x4 mode with the stock tires. They also handle weight better and seem to reduce body roll.
I had a RZR in the past and the CVT on the Mule is a totally different animal - MUCH smoother and it never seems like it is slipping like the Polaris. Granted the Polaris was a sport machine but I can't say I was a big fan of their CVT.