For the uses you describe, I'd want R1s....way better in the woods, and for tilling, etc. R4s are great for loader work, ride smoother, don't damage lawns as much, and offer great puncture resistance, but they almost never equal the traction you can get with R1s.
Before I sold my LS I was clearing a low area with the brush hog and nearly got stuck...it was a bit damp and the R4s just spun like crazy because the tread instantly filled with mud (even with 4wd and differential lock use). I put my other mower on my 2wd Massey which has R1s and it just cruised through the same area with almost no wheel spin at all....total non-event.