Are you seeking to improve your forward vision, or are you seeking to make yourself more visible to others? If all you want to do is pizz off oncoming drivers and riders, then the caliper mounted lights will be fine. If you want to improve your own ability to see, mounting the lights on a sprung portion of the bike up a bit higher will be much better.
I know there are a lot of Motolights fans around here, but I'm not one of them. I hate having a bike with those things coming at me even during the day, and at night they are even more obnoxious and irritating as they constantly bounce around with each ripple or pebble in the road. I place these things in the same category as excessively loud pipes; they don't improve safety as their proponents usually claim, but they do irritate the living hell out of others.
JNHO - Jerry