If your trails are so close you figure the R1's would work but the R4's wouldn't, you're probably going to be banging into stuff with the tractor, regardless of which tire you choose.
I think my problem is not having used a tractor at all and not being able to "visualize" what I would "know" after a couple of weeks of ownership. My trails fit my 60" Polaris Ranger side by side with room to spare...only issue might be some needed trimming of overhanging branches...which needs to be done anyway.
It is the venture off trail that I wonder the most about.
My soil is very gravely and quite dry since rain drains very quickly. I would likely get R4s but I think AGs would work well and maybe provide extra traction. I do worry a bit about the cutover portion of my land as there are many things sticking out of the ground from logging 15 years ago...
Thanks...TMR
BTW...my wife is quite worried about our blueberry bushes...we bought the most recent 40 acres last fall and had no idea it was full of blueberry bushes...had a bumper crop this summer...I have to find out what fall mowing after the bushes have turned brown...might do to next year's crop? That would be another thread
I will likely plan on a purchase in the late winter early spring as I have no plan to use during the winter...unless there is a special deal offered by Kubota and/or the dealer. Top on my list is the L3540...followed by the JD 3320.
TMR