I know the infomercials are cheesy, and many people here will talk shit against it...but I loved my bowflex.
I added 50lbs to my bench press in probably 6 weeks, let me target lots of muscle groups quickly and effectively, got my body looking VERY good.
What is most important in any excercise routine is that you stick with it, and that it's enjoyable to you (which will help you "stick with it").
Personally, I don't like (nor do I have the time) to go to the gym I joined. But when I had my bowflex, I used it EVERY day that was scheduled in my workout routine. I joined my gym on the day of the superbowl, and have gone maybe 15 times
Not only is it inconvenient for me to have to go somewhere to work out, I don't like the "gym atmosphere". Some people need that motivation where they actually have to LEAVE in order to work out...I'm the opposite.
Forget the cheesy informercials, it'll do anything the average person wants with it. If you want to look like arnold schwartzenegger then ya, you'll probably need something better/more advanced.
But I used it with great results. When I get the extra money, I'll be getting another.
My .02
*ETA* I did not get the top of the line model...I think it was the XTL with the lat pull down and leg excercises deal. I also upgraded to 310lbs because I could do 210 bench press quickly.