Quote Originally Posted by mikemex
I'm aware of at least two kinds of ISTp.

One is "hedonist". It's more extroverted, more sociable, less reserved, less intellectual. The sense of humor is quite dark; almost offensive. Is rarely interested in working; prefers to drink and be involved in other leisure activities.

The other is "expert". It's more introverted, less sociable, more reserved. The sense of humor is more "elegant" and less crude. More receptive to intellectual stuff. Likes technical stuff and be involved in "interesting projects". In general, enjoys working more than the other kind.

I have no idea which subtype is each; if subtypes exist at all. It seems to me that it has to do more with intelligence (not all ISTp are the same) level. Very intelligent ISTp are like very intelligent people of any other type: more interesting in doing something than just wasting time.
I agree with these descriptions. I've seen the same patterns, but I've found both 'types' to be highly intelligent. The hedonist variety seems to operate in inspired bursts of production and intellectual insight, but the depth and quality are equal to the that of the steady 'expert'.