How much time could you conceivably use this for?

What is the median use time amoung these devices?

I love the idea and on a different day might try to acquire one. But realistically it would end up in a drawer after not too long.

In all honesty, the fun is in programming them, not using them... I have one, but if I could find an emulator platform I'd be happy to forget it in a drawer. I don't get a lot of of opportunities otherwise to do minimalist embedded programming.