I do not think there would be a major difference in the clutch performance between the two machines. The JD ehydro to me is a great transmission. I do not know how the Kubota compares, but to me and with where I live, ehydro beats the PowerReverser tranny for ease of use hands down. I know several on our site have the PRT and are happy though so I think it comes down to how much one wants to spend and where he/she lives. Flatter terrain and more open spaces favor the gear drives a little more. My parents have two places, one in the northern NC mountains and one in the Piedmont area. I could easily use a PRT tranny at their Piedmont location because it is open and flat, but at their mountain place or my permanent place, no way. As far as pushing snow, I really like my JD. I have the Frontier boom blade for mine, and although we have had limited snowfall this year, it is really nice. I do not think Kubota has one of these, so one might have to go with an aftermarket setup such as Curtis, I believe (please check this). I believe properly ballasted and with appropriate tires, each machine would do fine. I have had limited personal experience with Kubota machines, but they have a good reputation. The biggest issue is the dealer with whom you work and whether the tractor offers the features you want and the price you need. Either machine would do a nice job for you. I prefer the Deere and have supported them due to my strong dealer and the nice features. They fit great and work great. The attachments are easy to switch and work flawlessly for me. The tractors have good to great power and are literally easier to operate than a car. I also appreciate the engineering and fit and finish of the Deere product. The Kubota shares this trait as well, though. To me, I have never been disappointed with any Deere tractor or UTV I have owned. To date, I have had 10 JD tractors/ mowers and they all have been great. Each has probably been slightly more than the competition in price, but has provided such good service I have felt my money was well spent. I do ask, though, that you consider a 3320 over a 3120 in the JD line. I do think you would be a bit happier.
John M