unfortunately where i workout at right now only has machines (2 minutes from my house) other than dumbbells. I REALLY prefer freeweights but i do have to say machines are better than nothing. You just really have to watch how you use the machines to make sure you use only the muscles you are working out with. Plus right now, for the most part i don't have a spotter, so when i get to into the set and can't do anymore reps, i can stop, drop some weight and continue for a couple more reps.
Like i said freeweights for the win, but when you are by yourself or it is all you have, you can get some good gains by them