old post, but...
Having used IAR and AVR Studio 6 and emIDE/Code::blocks. I sure want to to Teensy 3 (and 2) C++ development with a real C++ editor, not a simple text editor. I use Progrmmer's Notepad - but it doesn't do cross-file references and so on.
I read about the plugin for Window Visual studio - but from reading/trying, the only way to use that is via Atmel's Studio (for AVR and Atmel ARM), as I have no VS license and the Express editions don't allow plug-ins.
emIDE with G++/GCC - is just fine, if I could know how to get that IDE setup to go for Teensy 3.