Sam, I still believe that your tractor decision should be based on whether you are going to be working on 40 acres or 5 acres. You have to determine that first.
My brother and I bought tractors about the same time last year. (Sorry to bore you folks who hear me repeat this time and again) He has 17 acres and went with the 3710 hydro. He loves it though he wishes he went with the 4310 hst. I have 34 acres and went with a 5400. My tractor is just right...though a 6800 would have been just right even better! Sam, your thinking of bigger is better is correct. I've never wished I bought smaller. When you BOMBed your 2500 don't you still wish for just a little more hp?
When I bought my 5400 I needed a tractor right then...end of year and tax reasons. Plus the new M series (4900 and 5600 wouldn't have been delivered to dealers until March or so. I would have liked to have a fully synched trannie like Wens but I didn't have that option.
Sam, to me the best thing about the L series is the hydrostat trannie. It is wonderful to use. The best thing about the M series is everything else. I am not knocking the L series fellas, but for me, when I'm bush hogging, lifting, pulling, knocking over trees, etc. an M series is a more stout tractor.
The gears on my tactor are a pain in the ass, but I've gotten really good with them. Don't think too much about which gear I should be in, I just go there. Think a fully synched trannie like Wen's would be even better.
Think Wen said he puts his tractor in gear and leaves it there for an hour or more without having to change. Sam, I change gears all the time. I live on a mountain and a lot of my property is bumpy...but not as bumpy as it used to be.
As to the seat of a M series, it is much better than the seat of a L series. A M seat has a big o' shock absorber in it. He you hit a bump you gently bounce up a down.
Hope this helps some, Sam. Try doing a key word look up on 4700, 4900, 5400, 5600, 6800, etc. There's some good stuff that's been talked about in the past several years. MarkC brought up a good point a few days back, there are not a lot of folks on this board who have the bigger Kubotas, so getting info sometimes gets frustrating. Someone on this board just bought a M9000, when he asked for info don't think any of us could help him....we could only admire him. So take advantage of the archives, Sam.