The 310 was a blast to fly, and has alot of power.
I flew it for my initial multi training, and to get my Commercial Multi.
Yes the fuel flows are higher, so i guess that may come into effect if you are renting the aircraft on a dry rate. When i went through my training, it was at a mom&pop flight school where you paid a flat rate for the multi course (about 10 hrs + checkride).
Learned alot in the plane, and the single engine performance definitly beats the Seminoles & Seneca's i've flown since then.