TweetI use a combination of both depending on my goals. I can almost always machine more then I can free weight so that tells you something. I agree it's a totally different workout but trust me, both are effective. There are some machine exercises I love that free weights just can't replicate. Now if you getting into isolation and individual muscles, well that's a different story. I don't think you've wasted any time but you have made your muscles do something new, and that's always good.