The roller races are a lot of fun to watch -- more fun for the risk factor this time; racers will have to mind their technique and not just pound away.

Used in a space like a hallway -- where you can prop yourself up or nudge yourself straight if you're drifting -- rollers are actually pretty safe. This is my second winter with them, and I've gotten to the point where I use the wall only to start up and let myself off. Haven't tried to ride no-handed yet but I will try some one-legged stuff this winter.

The challenge of willing yourself upright and holding a straight line is something to look forward working out to, and made me choose it over a trainer. The resistance factor is a non-issue -- spinning a 53x11 at 110rpm on rollers is plenty tough for an indoor workout. The one thing you can't do is stand up, so a pause of a minute or two (at least with my saddle) is necessary for me approximately every 30 minutes.

More than smoothing out your pedal stroke, I think rollers actually train hip alignment. You quickly sense that the bike will drift in the direction of your hips -- and you'd be shocked how much your hips shift when you're, say, reaching into your pocket, changing your hand position, even looking to your left or right. Keep your hips straight and you can do all these things while pedaling straight in the sweet spot. Training yourself to stay unconsciously straight is invaluable for paceline or pack riding.