I have a 1999 Joshua F4 that I recently bought on craigslist. It only needed cables, chain and a new control for the rear shock lockout and I got it working pretty easily. It rides really, really nicely. There is quite a bit of bobbing when pedaling, but the shock lockout helps quite a bit with this. I just used an old thumb shifter as a lockout switch. Not sure what it originally looked like.
I have been using it for the last few weeks because the rear shock on my other bike (2002 Trek Fuel) was blown. I got the trek running and took it out today, and was a bit disappointed at the rough ride compared the the Joshua. The trek has air shocks, so it could be that reducing the pressure a little will fix it right up, but I was surprised at the harsh ride after my time on the Joshua.
If I had to take a long ride, especially with hills, the Trek would certainly be the way to go, but for a short ride on bumpy, rooty, singletrack, the Joshua is a nice ride.
Edit: I forgot the best part. Apparently, this bike came out at a time when Shimano was trying out something different and the right trigger shifter works opposite to normal. So, a long thumb push results in a harder-to-pedal gear, while a quick finger-pull, results in an easier gear. It shifts nicely, other then the time spent thinking about it.