I've been weight training for almost 10 years now. I'm finishing up my degree in kinesiology and will be starting my masters degree in physiotherapy so it's not as if I'm blowing smoke out of my *posterior* when I suggest you stay away from the Bowflex. One of the major problems with the Bowflex is that whatever bar you're using is in some way attached to a cable in order to supply resistance via the stupid rubber bands. This leads to huge problems when trying to vary your hand position on movements such as a flat bench press. Furthermore, without getting too in depth regarding motor unit recruitment and training of the nervous system, the use of free weights translates in to far greater functional strength due to the recruitment of the multitude of agonist/stabilizer muscles needed when using dumbbells or even a barbell for that matter (when compared to a rubber band machine).
If your goal is to train for strength you would be well served if you worked primarilly on major compound movements such as squats, bench press, military press, dead lifts, pull-ups, cleans, etc. Good luck doing effective cleans, squats, dead lifts, etc on a Bowflex.
Even if you're intending to focus on bodybuilding, the majority of your hypertrophy comes from handling heavy weights during compound movements as opposed to cutesy things like high cable biceps curls that you see so many morons in the gym doing ad nauseum (PS sorry if I've offended any of you morons who do high cable biceps curls ad nauseum
).