[Adriftpanda]

I perfer to train mainly with free weights but for certain exercises or for more of isolation movements, I'll go over to the machines.

As far as circuit training goes on the machine, my gym does have a "machine circuit training" station. Consist of some legs (seated curls,leg extensions), Chest (chest press), Back (pull downs). There might be some other but I just can't recall. And yes, I do see people using the circuit station training, but not often.

Start where you are comfortable, it wouldn't hurt trying it.