1st: Is there a thread on this subject already? I did a search but didn't find it.
My old camo line came apart this year so I went with the Cortland Clear camo at a modest price. There's a lot to like about this line, but the memory coils are irritating and I don't like the lack of sensitivity on slow retrieves. I have an Airflo hover line (not clear), and I feel every nibble of fish I am missing 
So, question: Is clear camo really better and which one do you find casts and fishes the best? Thnx, WR
I believe there was an extensive discussion on this topic in the past, but it may have been on the WFF site.
In my opinion, the fish can see a clear line or any fly line just fine. I do think the fish will be less startled by a clear line landing on the water than a brightly colored line, so that's a good reason to use a clear floating line or clear intermediate line. I prefer to use an intermediate line for casting & stripping flies in shallow water because the line sinks below the water surface whereas a floating line sits in the water surface film; when you strip a floating line, the line and knots will create chevrons on the water surface, which I think makes the fish more cautious.
Over the years I've become partial to the RIO Aqualux II clear intermediate line (now discontinued, but can still be found on eBay or other places at a pretty good price now; I recently purchased a half dozen of these lines, so I now should have a lifetime supply). I do stretch the line when I first start fishing the line, but it is usually fine after that for the rest of the day unless it is really cold, in which case I stretch it each time I start using it again. To me, the line has a nice supple feel to it, so it not only casts well, but is easier on the fingers when casting & stripping flies. The line also seem to last a long time before cracking.
I have a RIO Hover line, but it sinks so slowly that the only time I use it is at Rocky Ford, as my clear intermediate line sinks too quickly for that fishery. The RIO Hover line with an unweighted fly or slightly weighted fly seems to work well at RF.
I did try a RIO Aqualux camo intermediate line once, but just didn't like the way it looked. I suspect a fish could see that line just as easily as a clear line, so there was no advantage to using a camo line that I could see.
As for the clear intermediate versus type 3 debate, I like the RIO Aqualux II clear intermediate line for depths down to 7 or 8 feet, and deeper than that I'm using a type 5 or 7, so I've never found a use for a type 3 line, but I'm trying to keep an open mind on the matter so I don't get "unliked".
As for fluoro versus mono, I almost always use fluorocarbon leaders and tippets, but I'm usually casting & stripping. For strike indicator fishing, I can see that using a mono tippet might help, as it is more supple and less stiff than fluoro, so that might make it slightly easier for a fish to grab a small chironomid pupa pattern in that vertical presentation. I do feel that fluoro is less visible to the fish and is usually stronger than mono for a given diameter.