Gear gives you more HP, HST gives you fine tune preciseness, where you can creep very slowly to hook up implements, also very quick and easy to go from forward to reverse....Gear driven doesn't bother me if it gives me better control.
I was a gear only, kind of guy but now I really love HST (especially the older I get).
I would get a HST L3301 before a Gear Drive L3901 - but that's just me.