As much as I enjoyed my ride in your PA46, I have to disagree. For your mission, the PA46 is great. For my mission, it would be useless. You can fit more stuff in an Aztec, 310, or Baron due to the configuration and door differences. For this discussion, let's ignore the merits of single vs. twin and just assume you either need one or the other.
Dave, likewise, is thinking about his mission. The P-Baron is a good fit for his mission. As far as piston vs. turbine, I think it really comes down to a question of power. The piston engines produce power more efficiently, but have a hard time producing high power with acceptable TBOs. Hmm...