Uptaker,
I believe the 3120 would perform similarly to the 4310 tractor formerly. Based on the torque numbers and improvements to the ehydro transmission (if that is the desired one), the 3120 should be a good bit better performer than the 4210 of old. Essentially new 3020 series machines seem to correlate well with the next higher model of the 4010 series. So, for example, a 3320, with its higher torque readings would behave similarly to a 4410. I found my 4310 to be a bit weak on power for the big hills and heavy loads I hauled here, but it was a very nice machine and many of our fellow posters use and love them. Unless you have big hills at your place and do not need super good power to weight the 3120 seems OK. I have driven a 3320 and found it to be more potent than the 4310 I had, so from this, hopefully you can glean some info.
John M