I looked at both of these bikes. I purchased a Nirvana for my dad last spring. Also, I was considering both for my girlfriend about 2 months ago. They are similar bikes, with similar componentry. Trek owns GF, so they are essentially the same company. If I had the choice between the two, I'd test ride both and see which was most comfortable to ride.
Neither brand allows it's dealers to sell online, which means if you see one for sale the net, it's either used, or an illegal sale. As far as comparable bikes, I don't know, but any "700c" bike in that price range should be comparable. There are a lot available. You might want to look at the "Big Buzz" from REI. REI also sells a decent bike. good luck
thanks, I know they are the same company, but the components are a little different, would like to know which one has the better components. I am not too familiar with the components part, because I haven't worked on bikes for almost 20 years now.