Fred,
Your question was “is nymphing without an indicator going to improve my drift or hurt it?” The answer……it depends on the situation. I go both ways (with respect to indicators!) depending on conditions.
I like to use an indicator when I need to reach out and cast across several current lanes, because I can mend to the indicator like I mend a dry fly to prevent drag and get a longer drift.
In broken or off colored water where I am able to wade close to the fish, I usually high-stick or Czech nymph without an indicator. In deep fast water I don’t use an indicator, I use thin running line and use my sense of feel as well as sight for strike detection. I can control the depth of the fly and follow the contour of the bottom using the two aforementioned methods – a point that Pad made on an earlier post.
In shallow water, or when the fish are up in the water column feeding, I sometimes use a dry fly as an indicator. Also, sometimes while fishing shallow water I will put a pinch of Strike Putty on the leader / tippet knots to better see my line. I don’t know if that would be classified as an indicator since it doesn’t float or suspend the fly.
When midging in calm water with good light, I grease my leader and tippet up to 12” from the fly and use the tippet for strike detection.
In fast pocket water I use a heavily weighted fly I call a depth charge with a short leader and no indicator.
Lately, when I do use an indicator, I like the poly yarn rather than the Styrofoam ones. The yarn indicators splash less, cast well, can be trimmed down to any size, and are cheap (I make them myself). I’ve been experimenting with a larger yarn type indicator and attaching a string of small shot from just below the indicator down the tippet to the fly. I'm trying to get a more vertical drag free float – copying the center-pinning method. Still working on that one.
There’s no easy answer to your question, but I would say don’t listen to the guys who say never use an indicator to nymph, or the guys that say always use an indicator to nymph. IMO, you need to use the best-suited method for the fish and water conditions. Sometimes an indicator fishes best, and sometimes using just your leader works better.
Are you ready to go both ways Fred?