OldLefty wrote:
I've been fishing nymphs since '72 and, I confess, I'm sure I still have a lot to learn.
My professional statement is: No matter what you employ, whether it be a sighter built into your leader, an attached strike indicator (which includes the dry in a dry- dropper rig) or the line to leader connection, it provides you a means by which you can detect an abnormality/interruption in drift.
There are pros and cons with all of them. For example, with a sighter system fishing in windy conditions can be a problem since the rod tip is usually positioned high above the water and wind loves to push on anything; hence, the wind can push our flies right out of the drift. With most indicators on the leader the surface tension of the water will actually help to hold it in place on the surface and we get the drift we desire. And, as others have already stated, with most strike indicators which we attach to the leader we can adjust their position quickly and easily which is necessary to be able to vary the depth at which our flies ride to be able to effectively fish the varying depths and current speeds we encounter. It's amazing how much difference there is in recognizing the need for change and not doing it and actually making that change. And herein lies a drawback to using any indicator, dry fly in a dry-dropper included, which can't be readily repositioned. There are a lot of trout that will not be offered an opportunity to see your nymph. Sometimes that won't mean much; however, other times it can mean everything.
Oh, and to the statement about putting a split shot on the leader and attach a nymph at the end and fish, well, this is the way I fished for more years than I want to count. And, believe it or not, many who know me could vouch for the fact I fooled a fair number of trout over those years. As for strike indicators, I used what is now referred to as a sighter long before we were introduced to that term. And now, there's the drop-shot rig for fishing nymphs. It's great!
It all comes down to "whatever trips your trigger."