Slow is good! In many cases the subtleties and beauty of the tunes are more apparent. And, as you say, more control is necessary at slow speeds - dynamics and careful phrasing are required - more thought, in other words.

For dances, of course, the dance speeds dictate the playing speed. And, now and then, a hell for leather pace can be fun - but more in a rehearsed band context than in an open session, IMO.

I used to play the soul number "6345789" in a funk band. Our bass player and leader, Keith, would slow it right down till it greased and oozed sleazily along - sounded great. Drinks were consumed to it, babies were conceived to it...