Any career advice most appreciated - Front End Development vs Project Management

I suspect that a full time PM job is quite different than one where you are given PM responsibility whilst performing other duties.

Perhaps the deciding factor should be whether you prefer to be hands-on or not. A 'purist' PM has little to do with the product -- he/she manages resources, people's time, risk, budgets, etc...

I think it would be more difficult to switch back to a developer position after you've worked as a PM. PM methodology evolves slower than technology.