B~
The effectiveness IMO is important. Having teh guides in line & on spine or 180 out is critical. My barometer for this is a rod that my "friend" made for me a long time ago. Got into some nice fish and the rod twisted in my hand - right to teh spine. The guides are just off the spine, one side or the other.
Not exactly sure what you are looking for with on or 180 out.
Spin = weak spine guide side (inside)
Conventional = opposite above
Fly = either.
Does it matter - absolutely. Casting (power) Casting (accuracy). I believe teh fisher will unknowingly tweek the rod in their hand much like a golf club for accuracy. You tweak the rod cause you know how it feels twists etc from experience with it so you can get your plug exactly where it needs to be. Just like fireing that Daisy red rider bb gun. ("you'll shoot you eye out kid") You adjust where the round inpacts cause the sight is not adjustable. If on the spine then there is little to no adjustment.
Fish fighting
Effectiveness - on a boat rod done correct it gives a stronger rod to fight the fish or the bottom - I'm told you could even turn a boat around in the canal when hung up.
am I close to answering your question?