Ground clearance is not so good and you do need proper off-road tyres. It's also quite heavy to pick up if you drop it.
I took my moto-crossing for a charity event and it didn't last long. However, if you're careful and just going on trails, it seems to do the job.
As far as design goes, it won't break much if you drop it. Pedals can be bend back easily enough, but the levers are easily broken so make sure you loosen up the fittings so they can be easily twisted back. Of course, it will flood at the first sign of being dropped, so make sure the battery is well charged if you're planning on doing anything a bit risky. And don't use the kill switch and then spend ten minutes wondering why it doesn't start (easily done :-)).
"On that? You're nuts!" - My cousin's boyfriend
Current Bikes - Kawasaki KLE500 '05 (May 06)
Previous Bikes - Hyosung GF125 (Oct 05 to May 06)