I once read that a good way to learn things was to ask a lot of damn fool questions. I tend to do that in my fishing, whether I’m wondering to myself, trying something new, or picking the brain of someone who knows a lot more than me. Here are some recent points I’ve been pondering:
Is “pushing water” the most trite, overused, overhyped concept in streamer construction today?
How do all those stripers find my 1″ long sparse grass shrimp flies at night with no moon in water with visibility of under 2 feet?
Why don’t more striper anglers think in terms of matching the bait, and presenting the fly like the naturals are behaving?
When it comes to choosing lines and leaders, is there a more important question than: “What do you want the fly to do?”
If intermediate lines are the most versatile, why do the vast majority of striper anglers use only one presentation with them?
Is there a striped bass swimming today that cares if your fly turns over?
Last but not least: why the hell didn’t I get out and fish in the wake of last weekend’s storms?
If you want to consistently catch bigger bass on the fly from shore, fish how, where, and when most other people don’t.
currentseams.com 
In the same vein, I would love to hear your thoughts on the current trends in trout nymph construction: Do trout care about flash? Are slender, fast-sinking nymphs really more effective than buggier, slower sinking ones? Are trout attracted to resin coated wing cases?
Dwight, I view flash in flies the way I do salt in food: sometimes the chef gets it right. Sometimes the chef overdoes it. I like flash in some nymphs, whether in the form of a rib, a bead, or dubbing (SHBHPT, BH Squirrel and Ginger, Frenchie variant, just to name a few). Of course, how much that flash is going to flash depends on available light and depth. And there are many times when one of my tandem nymphs has no flash at all.
I take it those slender, fast-sinking nymphs you’re describing are Euro nymphs. In that method, one of the functions (if not the prime function) of the fly design is to sink the entire rig. Since I don’t Euro nymph (I’m a drop shot guy) it doesn’t concern me. “More effective” is of course relative. I can tell you I catch many, many trout with unweighted, buggy, non-streamlined nymphs.
Regarding resin-coated wing cases, why not? I don’t tie any flies with them, but have used them in previous seasons. Entomologists tell us that aquatic invertebrates will often use trapped air to surface. It’s not a stretch to imagine those bubbles might be reflective. The best way to test the effectiveness of a resin-coated wing case is this: take 2 flies that are identical save for one having a resin-coated wing case. Tie them on a tandem nymph rig. Fish them throughout the season. Change the position of the flies so that each fly gets equal time on top or bottom. The fish will give you your answer.
Hope that helps,
Steve
I too have had sleepless nights over these same questions. You are normal…for a fly fisherman…
Crazy is the new normal…
Agreed sir!
Do fish…any fish… know that I DON’T whip finish my flies? (I’ve only whip finished two since 1966).
Upon further review….no.