I was looking into getting one, a few months back, but prices have increased on used ones, which are very hard to find... I'll have to wait a while when fuel prices go back down some, or when I have a higher paying job...

As for longevity, looks like they will do 300K miles, and the timing belts need to be done 80K miles, but there are 100K mile kits which have a larger idler roller.