Personally speaking, I don't like a tractor with a clutch in the bellhousing, because at some point in it's life it has to be replaced whicn entails a split and lots of cost. Only thing in the bellhousings of my M9's is a damper plate to reduce driveline shock when shuttling from forward to reverse and the travelling clutch on my M's is a multi plate wet clutch, activated by a hydraulic circuit, there is no mechanical direct activation what so ever and the hydraulic circuit 'modulates' itself so the pack don't lock up quickly which eliminates driveline shock.
Does it work? Well after 5000 plus hours on them, I've never had to adjust either and the lockup pressure is in specification.
I ain't gentle on either one as they work hard when they work. Lots of loader work and lots of cutting raking and bailing hay. Because of all the rain we have beem getting lately, the hay is on the back burner (not enough dry down time to make dry hay bales) so I've been dead pulling out weed trees in my pine trees. Birds like to roost in them and poop out seeds and they grow and become weed trees that have to be yanked out, which I've been doing lately and the wet clutch makes it easy with no jerking and no riding a dry clutch. I just engage the shuttle (tractor is in FWA, differentials locked, I can lock both the front and rear) and out they come, roots and all. No muss, no fuss.
I bought one of those 'Brush Grubbers' and they work but a 2 foot length of heavy wall rectangular tubing with one end sharpened and a log chain with a hook on one end and the other fastened to the drawbar works better and is much stronger as well. Leave a bit of slack in the chain and when it gets tight and the sharpened end of the tubing bites into the trunk, out they come like a cork in a wine bottle.
The Brush Grubber takes 2 people to use, the tubing and chain just takes me to work... and the tractor of course.
Only thing better in my opinion would be a CVT transmission and clutch assembly but Kubota don't offer that in my size units, so I have the next best alternative.