Trust me, FITH with the lights on is no great woop. I spent part of a winter replanting plastic flowers in front of Red Flander's place, picking up garbage thrown from cars etc. and it's kind of seady looking with the lights on. Now off would be cool......
I've been through with both. Coaster Christmas 2006 we did several laps thro' with the lights on. It really gives you an appreciation of just how big those drops are -- especially right after the train tunnel. The lights off one was at the end of the day way back when I was younger and my brother and I were the only ones on the train and we asked if they would do it and they said "sure". It was rather freaky. No sound or anything.