Lightrails - next big thing in reef lighting?

[mark]

Not that I would do it but wondering something...

I have a tank that is ~6' long with 2-250W pendents with T5 on both sides. Would I be able to replace with one 250W on a light rail going end to end? I see the gain in dropping one pendant and ballast (save on energy and less heat) but there's obviously a drop in the overall light the tank would receive. See increasing photoperiod, going to 400W etc, but wondering how this would be correctly adjusted from the fairly typical setup (bulb for every 2-3' and 8-9 hour photoperiod)?