I just bought one of these ($33.99), even though my factory clutch cable was in fine condition. I figured I'd give it a shot, because who doesn't what a lighter, smoother clutch pull? In fact, right on the package, it says "The increased efficiency of T3 cluch cables provide a lighter, smoother pull, and significantly increased durability over conventional OE cables." Sold. If nothing else, it was a good time to clean and lube the clutch lever pivot area, inspect the old cable, and add the insurance of a brand new one.
The cable comes pre-lubed from Motion Pro, and has a little lube port that is just too small to fit the red tube piece you find with a lot of spray lubricants, so you have to position it the best you can and hold a paper towel around it while you spray. It is covered by an o-ring at the top of the cable to keep the elements out. It's a nice feature, and I threw a little Tri-Flow in there for good measure.
One thing I did before removing the stock cable was measure the pull tension. I used a two-or-so inch piece of aluminum that I held on the front side of the clutch lever, with wire around the front side of it and hooked into a fish scale behind the grip that I pulled towards the rear of the bike. I used the aluminum piece so that the wire wouldn't drag on the grip - only the tension force of the lever actuation was measured, and there was no flex in the wire.
The lever pull force with the stock cable was an average of 12.5 lbs.
Once I got the new cable on and adjusted, I measured the pull force with the same method and at the exact same point on the clutch lever (lined up with Sharpie marks). The lever pull force with the T3 Slidelight cable was an average of...12.5 lbs.
Who knows how accurate that fish scale is, but what's important is the two pulling forces are equal. The action is not noticeably smoother, and the "significantly increased durability over conventional OE cables" will likely not be determined for years. I will measure the pull force again after a few rides, in case there is any break-in period.
So if you're in the market for a new clutch cable, save your money and buy the standard $18.99 Motion Pro cable (or $21 for a factory Yamaha cable on boats.net). The only benefit I see with the T3 Slidelight is the little lube port, which is handy if you don't have the tool to properly lube cables. Then again, for the difference in price for this cable, just buy a cable luber tool.