imho, a lot of the function and performance of a hill-style longbow hasta do with the longbow's design and the bowyer and the materials.
i've had all three types - backset, straight and bellyset (string follow). overall, the backset typically adds some speed, the string follow adds some "stability".
any limb design can be made harsh, stacky, stiff, shocky - again, look to the bowyer, design and materials.
my primary hill-style is a 69" david miller with backset, and it's every bit as smooth and stable as was my (rip) 70" hill tembo with string follow, only the miller is easily faster (both, very near the same digitally measured holding weight, with the miller being a bit lighter).