The 337 looks like a fabulous aircraft. When (if) the readies avail themselves, one shall be mine!
I'm told all the Piper light twins are like this.
My impression was that the Seneca 1 was definitely more tricky than the Seneca III which was more difficult than the Arrow t-tail which I was told was difficult.
However, the Seneca I and Arrow both have very heavy elevator forces in common, you think you've run out of authority but with more determination you discover there is movement yet. Just that judgement, probably very subjectively on my part, seemed to be more difficult in the Seneca 1.
Perhaps the Twin Comm is like the Seneca 1? The Seneca 1 definitely likes power to remain on until starting the flare with a fair amount of rearward trim. The rearward trim does not cause excessive control forces when going around which is good. It should be positively landed on the mains (greasers just increase the ground roll) with a good flare and the stick hard back as you brake until the nose cannot stay up any longer. This produces satisfyingly short landing runs.