Thoughts on Resistance Rods

I am just wondering what others think of strength training with resistance rod type machines. I bought a BioForce machine (similar to Bowflex) and have been using it for a couple of days. I find that I can lift heavier on the rods that with free weights and I don't get the least bit sore after a workout no matter how hard I push myself. This is puzzling to me because I haven't worked out in a year so I know I should be "feeling the pain" after any activity at this point. Even heavy yard work leaves me a little sore the next morning, but nothing from ts resistance machine.

Any advice, opinions, ideas???