Depends on you goals
Here are some random thoughts on the Bowflex. I've been a Bowflex user for 8 years. I have one of the older models (Power Pro). My brother started with the Power Pro and upgraded to the Ultimate (Bowflex gave him a $1000 trade in on the old machine, but I don't know if they still do this or not). We both like our machines. My goal was to maintain muscle tone and add strength training to my cardio routine, but I had no ambition to try to look the guys they use for the comercials (I doubt these guys built their bodies on the Bowflex alone). I went with the Bowflex because it is one of the lightest weight and most versitle machines out there. Plus it is relatively safe and you do not need a spotter. If you need to move it out of the way it takes about 2 minutes for one person break it down and to move it. Other machines are pretty much a permanent fixture once you have them in place. I think that free-weights are still the gold standard by which all other equipment is measured, but they come with the price of being heavy, hard to move, requiring spotter for some excercises, etc. The Bowflex is techinque sensitive, and you really have to spend some time learnig how to use it or you will waste your time. One advantage over some other machines is that the resistance is not supported in any direction. Therefore you work many of the little stabilizing muscles that some machines neglect.