In addition to moving the shift points up a bit, it also was supposed to make them a little more crisp. On my old 87 I noticed it most when driving very gently. If you tend to put your foot in it anyway, you won't notice much difference if any at all. You also probably won't notice much difference in economy, but the comfort setting might get you a little gain. There's no gain in highway mileage once you're up to fourth gear anyway. If you're pulling a load, put it in power mode anyway. If you're pussyfooting down an icy road, you might find comfort mode less likely to break out. I usually kept mine in comfort mode, hoping for a bit of extra gas mileage, but it's mostly a matter of taste.