So far most issues have been with systems like the power steering, and misc. electronics/electronic bits, the Sequential Electronic Tranny had some minor teething pains, but is pretty solid now, all issues that have shown so far have been covered under warranty. BRP has lots of experience in the systems on the Spyder (except the stability control/traction control/ABS which are new to the Spyder) on their lines of CanAm four wheelers and Ski-Doo snowmobiles. BRP has an excellent reputation for delivering the most features for the dollar in both of those areas..
The Rotax engine is rock solid. It has been used in Aprilia sport bikes for many years and has a fantastic reputation for durability and ability to take abuse (and mods) and keep on ticking.
New or used is a matter of choice. The warranty is of good length, so most used ones are still under warranty, and you can purchase and extended warranty for a reasonable price (an indication of how dependable BRP feels the Spyder will be).
Spyders are not like bikes... not dropped (when you forget to put the darn kickstand down
) or put on their sides when you unexpectedly hit sand in a corner.... so they tend to take miles much better than two-wheelers. There are used ones for sale right around 10K right now, one of the sites users picked up one recently for just slightly north of 10K that even had a Corbin seat and side bags. I just saw a yellow stock low mileage 2008 sell in Springfield, Mo for $9100.