IM with nicb on this one ,adapt your rigs to suit the situation.
having fished a lot of clear waters where it is possible to actually watch the fish feeding has given me a totally different outlook on rigs.
many times ive watched as a carp has eaten all my freebies and totally ignored my hookbait.
on a certain lake where criticaly balanced rigs were in vogue i have watched fish fan the baits before picking up the ones that didnt move.
its sometimes enough to make you think about giving it all up
i do use pretty basic rigs for most of my fishing usually line aligned or with shrink tubing as i have to be happy with the turning action.
i believe that virtually all carp however wary will on occassions feed strongly without caution and simple rigs will catch.
its the challenge that keeps you going back,what are the carp doing under the water,has your rig been sussed,have you been cleaned out,do i need to change rig,pop up,critically balanced? bottom bait?
there is no deffinative answer
its a thinking angler that is the better angler.