When my B2650 was purchased, it was spec'd with turf tires. As a deal "closer" I added a set of industrial R4's at a price I couldn't refuse. (My older John Deere 750 turf tires were pretty soft so I thought I needed both kinds for the new Kubota.) The kubota turf tires are so heavy duty compared to the old John Deere turf tires that they stay on the Kubota 95% of the time.
I'll put the R4's on only if I'm going to be using the backhoe for an extended time or will be working in the woods with cut off brush stubs or unseen metal, other hazards, etc. The R4's are nice to have.....but if I had known how tough the turf tires were.....I could easily have gotten by with just the turfs. But the R4's are recommended for use with the backhoe.
Otherwise the turfs stay on year around. With summer mowing, roto tilling, cultivating, loader/grapple work, etc. Wintertime with a snow pusher blade on the front and 3 pt blower on the back, the turf tire's traction has been great. (except on pure ice). My use is all on level ground so may differ from other's use on hilly terrain.
I have found with a BXpanded "Piranha Tooth Bar" added to the front of the loader bucket there is no problem breaking out and loading hard packed dirt, sod, gravel or whatever from piles and most other situations. (With 4 wheel drive engaged, low gear, rear ballast, tooth bar and turf tires.)