Just like to second the votes for unpressurized alcohol... I have also noticed the condensation problem but I haven't found that cooking takes significantly longer (we have a CookMate 3100, two-burner). The biggest problem is evaporation, so it's important to replace the gaskets after the burner cools. The best thing about it is how it's easy to explain to somebody new how to use it.
Speaking of prudent mariners -- a prudent mariner using a pressurized alcohol or kerosene stove would be sure to adequately preheat the burner
We used to use pressurized kero and always preheated *twice* to ensure no flare-ups.