I'm a roadie, have a buddy into mountain biking, he keeps sending me gopro vids of his rides and it looks pretty cool, I'm looking at 2 cannondale f900s, both 10 yrs old and in great shape, little use, one is 300, the other is a lefty for 350, pretty sure they are both either 1999/2000 models.

Which one would be a better choice? I would say both are in very good/exc condition
The lefty looks cool..