I flew both and would seem to remember the 310 as being the thirstier of the two but cannot swear to that. It certainly sat higher than the Commanche and was the easier to land, didn't have the large nosewheel which had a tendancy to sometimes make contact early with students and would result in some exciting 'wheelbarrowing'. We had six of the early versions at the school without the contra rotating props for multi training, they had a VMCa of 90 kts and engine out below that speed produced interesting results. Part of my checkout as an instructor was being shown a spin in one. I was still pointing at the placard expressly prohibiting just this when it started, very rapid with major loss of altitude, recovery was standard. Chief pilot simply said 'someone sometime will do it to you!' He was right... twice. Having taken the point to heart, both occasions we had plenty of altitude. Both were during engine out below VMC which we were obliged to cover in the sylabus. Both students, had reacted by jamming forward the live throttle and stamping on a rudder pedal, unfortunately the wrong one, full power on the critical engine with little rudder authority did the trick. The one we came out of by retarding both throttles and standard spin recovery, the second however was far more diverting/ interesting. On entry the student gave a scream and flung himself across and threw his arms around me. I was attempting to pull back the live engine which he had firewalled but he was firmly preventing me and had his head in my lap. The altimeter was unwinding like crazy and I made like the hulk and managed to unwind him and then recover. He had the grace to be slightly embarrased about it for a little bit, but he then decided it had been very funny. I suppose that was one way of looking at it, but I certainly have never forgotten it. But a fun plane, looked great and I enjoyed flying them.