I'm with you hockeyplyr--I don't think ls is a neccesity. Yes it is beneficial, I think we all understand that--but I see people told time and time again that cc is horrible, or starting the nitrate blame game. Some days it's the cc, others it s the equipment. Quite frankly I think people with high nitrates should be blaming only themselves for overstocking, overfeeding, or under maintaining. Anyway-fact is cc does require more maintanance, it needs to be vacuumed. It shouldn't be used if your planning on housing sand burying type fish or inverts. It does require alot of rinsing before use. It also will become as "live" as any ls after a while (anything used as substrata will) , and therefore will be a biological benefit if properly taken care of. CC is also a huge ph booster, so take a look at your water when making your choice.
While ls is the primary choice of hobbyists these days (at least with the reefers and as well it should be) it is by no means as "evil" as some make it out to be.
All things to consider when choosing.
After all that, I say reef=sand, and fo/fowlr=cc
Good Luck