For long term usage however, you would be advised to start transitioning to the Teensy LC (or 3.2 or even 4.0). Paul has posted that the Teensy 2.0 is nearing the end of its lifetime, so for new development, it would be better to switch to a newer chipset now, rather than need a replacement Teensy 2.0 in 2-3 years, only to discover it has been discontinued.