Here's a roller story ... an LBS owner is totally into fitting. He got a whole bunch of high tech equipment from Trek. He offered to do a complete fit on me for free because he was trying to learn the equipment. Of course, I said yes. So, I get on the bike and do whatever he tells me. After awhile he says that his equipment allows him to measure the efficiency of my spin. He says that a recreational cyclist is really good if they hit 60% efficiency. Then he says, "You did 85% with no imbalance in your legs. How are you doing that?" And, I say, "Well when I first got into cycling I learned to train on rollers." He responds, "Of course!" I was 69 at the time. I think that's what really threw him.