For me the most annoying part about switching CAD tools is the libraries, the tools themselves are all pretty much the same you just have to navigate your way around, be it EAGLE, DipTrace, KiCAD, or even Altium.
WHA?! OK, obviously I am talking about simple boards with no high speed design and it will take a few days to learn how each tool does it's layer stackup management and what they call each layer etc etc, true, it's a learning curve, but depending on what your requirements are, might not be that big a learning curve, especially with online YT videos giving step by step guides to creating projects start - finish in these various tools.
That aside, what I did find however, when moving away from the dearly beloved (EAGLE 7 R.I.P), that some of the other tool creators have realised what a complete mockery Autodesk have done to EAGLE, given us the ability to import (with minor tweaks required) EAGLE libraries and projects, now they are not perfect, 85% I would say depending on the tool and your first thought is WTF has it done with this, but if you spend a few mins looking at it, it isn't too bad.
I believe KiCAD have just announced an importer for EAGLE with it's upcoming v5, and DipTrace offers a discount for users switching from EAGLE (not sure what ver) to DipTrace.
I still have 7.7 for legacy stuff, and some i have re-done with a different tool.