I have to throw a wrench into this discussion, well, sort of.
The seat in my old 5030 HSTC (I traded it on a M9) left something to be desired. If I had kept the tractor another year I would have replaced the spring/shock assembly with an air-ride seat base (yes, they are available and with swivel too).
My stock seat in the 5030 was all right, just all right and nothing more. I didn't care for the forward tilt of it, without the safety belt on you felt as though you were going to slide into the steering wheel and while traversing rough ground it was bouncy no matter how I adjusted the weight compensator. The back compartment was nice, the armrests were okay. There was no adjustment for the armrests either up or down and they were of a hard black plastic (grained). Looked like big stoogies (cigars). The seat cover was okay but I immediately put a sheepskin seatcover on it. This wasn't a casual use tractor, I used it for haymaking so I spent long hours in the cab. All in all, the seat was middle of the road, nothing excellent, just average. Like I said, a nice upgrade would be an air ride seat base, or the seat that's in my M9. As soon as I sat in it, there was a difference of night and day. It's a Gramer, air ride (no swivel), adjustable armrests tilt, lumbar nice velour upholstery (no pocket on back). The seat don't swing forward so you couldn't access the back anyway. The M9 is an ag tractor and the sole reason the seat hinges forward on the 5030 is so you can interlock the PTO when you are out of the drivers seat. There is an OPD under the seat that senses weight and if you come out of the seat, the tractor shuts down. If you want to operate the tractor on say a grain leg, you must start the tractor, dismount, walk around the right side, lift the seat and reach in and engage the PTO lever. On the M9 you just engage the PTO, standup and exit the tractor. A buzzer sounds for 15 seconds...that's it. I guess Kubota feels that on a tractor that's expressly ag in use, the OPD is not needed or wanted.
With me, the seat is just as important as all the other bells and whistle. A poor or middle of the road seat can and will make your tractor time less than enjoyable.
If you want to experience a really poor seat, try sitting on/in a Manhindra. The seat is about on par with a church pew. /forums/images/graemlins/grin.gif
On a scale o0f 10, I rate the:
Seat in the 5030 Cab Model- 4
Seat in the M9HDCC3- 9
My Western Star air ride Bostrum- 10+