Question Everything: Practicing fundamentals

When left to your own devices, what do you practice?  Are you more likely to:

- Improv/solo/play riffs?
- Play through a piece or chunks of a piece?
- Practice movements of a piece?
- Work on fundimentals/rudiments?

I find that I always have something to learn practicing the fundamentals, on straight beat, triplets, and doro/don tsuku, especially.  I try playing them faster and faster, being aware of what my body is doing and what it's trying to do.  Aware of where tension is building up and how I can release it.  Aware of where my technique is faltering and what adjustments are making things worse or better.

I think as long as you're practicing something, you're helping yourself get better, but I wonder how much better people would get with more focus on fundamentals.  This really isn't a critique but an honest question.

If people took more time on basic patterns and less time doing improv, pieces, solos, etc., would their technique get better at a cost?  Or would things come easier down the line?  For example, instead of thinking about what patterns to play, would working on playing faster (and evenly) help make the connection between what you want to play and what comes out stronger?

I realize this isn't a fully-fleshed out concept, but I was just thinking about it.  And you should too!  :)