I have owned both machines in question, and I even had both of them at my house for 3 months.
I can say initially I didn't like the HST of the
L45 as much as I liked the GST on the
L39. By the time I sold the
L39 its operation was second nature. I NEVER used the clutch unless I was operating in really tight areas. Otherwise, the shuttle lever was all you needed. The GST had a definite advantage traveling. It had more gears and you could tell less drivetrain loss so it powered up the hills better than the
L45 does.
Beyond that...I'll take the HST ANY DAY OF THE WEEK after owning the
L45 for a full year now.
The HST + on the Kubota has some really nice features. Worried about that jarring stop when you return to neutral pedal? There's a dial for that. The dial adjusts the sharpness of response. I actually find myself using the dial often. Instead of a shuttle lever, there is a lever that "splits" the range. Excellent when the going gets tough. You touch down and there is significantly more power without having to stop and change range. The auto throttle is excellent. It turns the HST pedal into a real accelerator pedal. This is great for transport. Did we mention the "Crawl" feature from the backhoe seat? Digging a trench with the GST is a gymnastic exercise.
I find the HST invaluable when using pallet forks. The precision is excellent. Working in the snow or slippery conditions the HST is king. Dial down the response and you can really manage available traction well.
I thoroughly enjoyed operating my
L39. There was something to the orchestra conducting you had to do to operate that machine well that I really enjoyed. On lookers were always impressed with the motions.
The
L45 is enjoyable, and less stressful. It's also much simpler if the wife needs to use it or you need a buddy to run over and get the machine. Everyone understands "push and go".
The best advice is to go play with them firsthand. About the only advantage of the
L39 is the price. Personally, I'm glad I made the swap to the
L45. It is WORTH the extra cash.
ac
PS Be careful whose advice you read and heed. The Kubota GST is a very unique monster. Not a lot of guys have true firsthand experience with it. The GST has significant differences compared to most "gear" machines. These differences really aid in productivity. The step from traditional gear to GST is probably as significant as the step from GST to HST.