I think renting was a good idea but for the type of things you plan on doing a 30hp tractor is too small. One thing you will need to remember is if you have a cab you will want AC. Just having it alone would mean adding an extra 5hp IMO. A 7' brush hog is going to need at least 35hp at the PTO, that's at last a 45hp tractor. Once you get in that range the HST wine is nothing like what a smaller tractor will make. HST will require at least 5hp to 10hp over a geared tractor. I personally wouldn't go with a geared tractor unless most (75%) of what I plan on doing was going to be shift into a specific gear and leave it there. Stuff like loader work would drive me crazy trying to do it with a stick.
My backhoe is 'shuttle shift' or sometimes called 'power reverser', very similar to GST. You pick the gear and then a level shifts between forward, neutral, and reverse. Once you get over 60hp it's pretty much your only option vs gear. It's like an automatic car. You have to rev the motor up to move. This means that if you are doing PTO work (like a brush hog) when you slow down to take a corner or turn around the attachment also slows down. It's also why others are talking about the hand vs foot throttle. With HST you set the RPMs you want and then control the speed the tractor moves forward with the foot pedal or cruise control lever.
) do when we need a specific (say 2400 in his example) rpm.
