Johnny,
No, I wouldn't buy a service body again.
I bought that F450 dually (15,000 pound GVWR) with a 460/ 5 speed for $2850, and $1100 for various bits. At the time, I had a 1/2 ton as a tool truck, and my F600 chip truck (22K or so GVWR). I needed something heavier as multi-purpose vehicle that provided back-up to either truck. I could put a 261 with a 20" bar, tops into a box. Not great. I thought of putting a shelf in the box for bigger saws, and chaining them down. The mini would fit under the shelf.
It pulls 5 yards of chips and the 4400 pound chipper or the similar weight of mini and chipper without caring much. More power, and way more maneuverability than my F600, but less capacity. Suited to pruning jobs as a one-man show, if needed, as sometimes happens.
Ideally, I'd trade in all 3 of my trucks and car for 3 trucks and a dump trailer. For now, I'll stick with what I have.