I do nymph quite a bit and usually use an indicator. I guess I don't see the difference with or without when it comes to currents. Usually, I place my indicator on my shock leader or just below it at the beginning of the leader. If you're fishing a floating line, with the indicator very close to the fly line, that leaves typically anywhere from 7-9' of leader. So if I remove the indicator, I still have the floating line subject to the current at the top of the water column.

So I guess, the way I fish, indicator or no indicator doesn't much matter unless your worried about the indicator actually spooking the fish.

I fish a wild trout stream quite often that holds mostly browns with some rainbows. Not big water at all. I have found that even during non-hatch periods, trout have rose to the indicator. Maybe they're spooked by it at times it's hard to tell.

Stow