What do most of you prefer for heaters in drift boats?

The basic Mr. Heater units seem to be the standard.

The optional Willie Forced Air unit appears to be a Mr. Heater radiant unit with a 12v fan behind it. Anyone know for sure?

Has anyone tried the Mr. Heater "Big Buddy" with the battery operated fan system (radiant heat + convection heat)?

Any other suggestions or good ideas?

I'm considering trading in my hot water bottle for more technology.

Thanks
OD