[yummyfajitas]

...you won't get the publication record you need if aren't motivated to do the work, and you won't be motivated to do the work if you don't enjoy what you're doing.

The point I'm making is that if you are unmotivated in elliptic PDEs, you'll probably be unmotivated in control theory as well. The fact is that research is research.

You might hate experimental physics and love theory, or hate computation but love experimentation, but these distinctions between subfields (condensed matter vs photonics) that seem huge in academia are not that big in reality.

If these small distinctions can give you a big advantage 50% of the time, it's a tradeoff worth making.