I have to agree with the others. I have a 2015 on the lot (with a woods loader installed) and with the HST. In rough terrain and brush, a 48" cutter would be a good match. Down here, when working heavy cutters, the HST tends to run the oil a bit hot. A smaller cutter would give your HST pump a bit of a break and add to its life.
Just an opinion, I have no solid data on this at this time....
Tractor Tom