Not recommended
Just look in your local Craigslist or buy/sell classified site, you'll see tons of bowflexes being sold second hand. Why? aside from poor quality (2 major product recalls with related injuries), and poor design (the bow's resistance curve rarely matches the strength curve for most users and most exercises); the whole "bow" thing just doesn't feel natural. It's the brain, you can't help it.
While progressive resistance can lead to slightly better results, bowflex twists the data from studies to make it sound like their equipment is proven to be more effective than traditional weights, that is just not the case.
Want a good example? a 5 foot 9 inch tall person may find the bowflex adequate for the squat exercise, while someone who is 5 foot 2 inches is not able to get the bows to bend all the way, thus reducing the amount of resistance available. Or someone 6 foot 2 inch may find the resistance gets too hard too fast because of their added height, and a limited range of motion.
Then there are the bows. They do lose strength. I've read on Bowflex owner's forums that they have found the rods weaken, from actually testing them. So while you think you are getting stronger, the rods may just be getting weaker.
those are just a few reasons, go to yahoo groups and search for fitnessfraud, there's lots more info there.