JK, Spec wise, they are basically the same; weight, lift, HP, etc.
So you sould check to see if they are both; Hydro or gear, same setup, etc.
Then go with the best deal or stay with the L3800 if you do not want the Tier 4.
Welcome to OTT Kasey from Alabama.
Since you have a gear driven tractor, you could probably get by with Super Tech or regular UDT.
Yes, as Karl said, most people use Rotella.
Best thing to do is get an Operators Manual and Workshop Manual.
You could try: http://kubota.servicemanualvault.com/...
On my tractor, all I have to do is put the "Range Shifter" in to neutral and I can stand up or get down off the tractor and the PTO will continue to run.
Here is what my Tiller Manual states: "15. Do not make turns or attempt to back up while tiller is in the ground. See important note below."
"IMPORTANT: Turning or backing up with rotary
tines in the ground will damage the tiller."
So I ALWAYS pick up the tiller before turning.