JDM Spinning Line? Really? Yes, absolutely! If you're getting a top quality Japanese reel and an exquisitely designed Japanese rod, why use just any old line?
The line discussions on various internet forums are interesting. It seems the bass anglers mostly use braid. They are sold on the casting distance gained from the small diameter, the sensitivity gained from the lack of stretch, and the ability of the braid to cut through weeds. They talk of 20, 30, even 50 pound braid. For really big bass in really thick cover I suppose braid has its place.
On the panfish forums you see lots of comments along the lines of "it's cheap and it works." For fish that are not known to be line shy and don't generally get over a pound (maybe two for crappies) that makes sense as well.
And the trout guys? Again, the forums are almost all fly fishing forums! The few comments you can find about spinning line tend towards buying 2 lb line because trout are line shy or buying massive spools of 4 lb mono because that way it's cheaper to change line frequently (which guys have to do because their spinners cause line twist).
From time to time you also run across a statement that a particular brand of 2lb test line is really strong compared to the others. That pretty much means it isn't 2 lb test, doesn't it? I once questioned one of those comments and was told "it's 2lb test diameter" so it's OK to call it 2lb test.
The only problem is that it isn't 2lb test diameter - at least not the diameter of Japanese 2lb spinning line. It's actually between the diameter of 4 and 5lb Japanese line. No wonder it seems strong, but is it as strong as the Japanese line? Who knows? You can't believe what it says on the package about the strength. Can you believe what it says about the diameter? The point is that you don't know what you're getting. I was also told it was "industry standard." If the industry standard is misleading labeling, I think I'll shop elsewhere.
But that does raise another issue. Japanese 2 lb test line actually is going to break at 2 lb, not what you're used to with domestic line! The line is wonderfully thin and I would absolutely use it if I was fishing the Daiwa .8g Vega spoons. However, for sinking minnow plugs, which are going to run over ten bucks a pop, I'd choose a heavier line (and I'd check for abrasion from rocks and trout teeth fairly frequently).
No one mentions premium lines other than a few of the bass guys.
Personally, I think that is penny wise and pound foolish. If you are enough of an enthusiast to buy top quality equipment, gear you cannot find at the local WalMart, why try to save a few pennies on the line - which after all is the only connection you have between you and the fish? Thinner line casts better, but you do want it to be strong enough for the fish you intend to catch. If you want your line to be both thin and strong, I would look to JDM spinning line.
I find it interesting that Sunline, one of the largest and best known line companies in Japan, has changed the lineup of their Troutist series of lines, which are designed specifically for trout fishing. They used to offer braid but now their trout lines are all nylon except for one intended for use in lakes. Most of their lines are colored. What do they know that we don't know?
For years, I have been a dedicated line watcher. I never fish with clear lines. There have been many, many times when I have detected a strike by seeing the line move even when I didn't feel a thing. Face it, if you are reeling in a lure, and a fish comes up from behind and takes it but doesn't stop or turn sharply to the side, you might not feel even a tap. Often you can see the line move, though. That is even more common when fishing slowly with small plastics. Seeing the line move sideways, without feeling a thing, happens a lot more than you would think if you've only fished with a line you can't see! If you only fish by feel, you will miss fish.
I'm not sure that is the primary reason for the hi-vis Japanese lines, though. Perhaps the major reason for hi-vis line is so you can see the flight of the lure and stop your cast when the lure is over your target. You definitely want to stop the lure's flight if it has overshot your target and is heading for a streamside bush. You don't have to save many lures to pay for a whole lot of line!
The lines that Sunline has designed for fishing in the Areas (stocked pay-to-fish lakes) are either clear or smoke gray, or have alternating lengths of hi-vis and lo-vis line. On the one hand, the Areas get very heavy fishing pressure. On the other hand, though, when casting into a lake, you rarely have to worry much pinpoint casting, and almost never about the trees and bushes on the far shore!
I make it a practice to add some clear tippet to the end of the hi-vis line, just in case the bright line might alert the fish. I'm not convinced that it does, or at least, not convinced that it does all the time or in all conditions. Once while fishing a small stream in Montana I ran out of tippet so I tied the bright green Sunline Troutist Wild spinning line directly to my spoon. I kept catching fish at about the same rate, so the wild cutthroats in that particular stream on that particular day clearly were not scared by the line.
I still add clear tippet, though - a length about equal to the distance from the rod tip to just in front of the reel - just in case. Maybe it's like wearing camo clothes. It might not help but it sure can't hurt!
The hooks are sharp.
The coffee's hot.
The fish are slippery when wet.