Gavinfred1,
I was in the same boat you're in on these models. Have you driven them at all? I really wanted the GL3940 but after I drove it, I found the DK much more comfortable to operate. I didn't like the way I had to turn my foot to operate the GL's HST pedal. This is an odd question but how tall are you and how long are your legs?
I saved b/w $4500 & $6000 (b/w the 3 different Kubota quotes) by buying the Kioti DK40SE HST. You'll love the rear 3pt control when it comes to hooking up your attachments!!!
The DK is heavier and it out performs the GL3940 where the FEL is concerned!!! Another point is that the Kioti warranty is longer than the Kubota.
I asked 2 different Kubota dealers about the "Auto-HST" feature.....other than being a really "cool" feature, what was the benefit of it, outside of fuel economy, they both admitted it was just a really "cool" feature. Not worth the extra $$ in my mind.
Don't get me wrong, the Kubota is a great product but for me, the Kioti was the best bang for the buck!!!
I have 5.5 acres and I'm helping out my father-n-law clean out a fence line right now @ his place (on Saturdays) and I used my pallet forks this past weekend. WOW!!!! It was amazing the crap I picked up with the forks!!!
Anyhow, hope this helps and good luck!!!!