Wow that's interesting wavewolf! Excersizing can help with depression huh? That's great for someone who wants alternate solutions to depression instead of using medication.
A smartdrive & freewheel would be totally worth it! Might as well take care of your body as much as you can so that'll be perfect for you.
My doctor said that extended periods of extreme sport would be equal to the "big-time" anti-depressants, actually proven in research. Principle is that triggering regular release of endorphins restores the brain's chemistry to balance. It worked for me! And I have wondered if being so physically active has helped keep depression away through the ordeal of paralysis. My definition of "extreme sport" is quite a bit modified now!
Even with all the percs, this manual chair setup is so much less expensive than a power chair and accommodating vehicle, and gives me a lot of flexibility in how to utilize my resources. I am really excited!