Yes, I have.... See it's quite easy to remove a Fays2 for a PHB. Have you?
Level of experience here isn't even a matter, experience with both types of setups is. I have it. Others have it. There are quite a few folks on S197forums, and Mustangforums.com that have put Watts links on in lieu of their PHB's and found a marked difference--and many aren't track rats.
You drove a lot of cars. Fine, so have I. Often 12 a day. You might well have driven a Watts car... but in reading your statement, it's pretty clear you did so in different cars, which have different setups and personalities. I've driven Watts links vs. PHB's in not one, not two, not three, but in 4 different cars after they had PHB's (and had driven all of them before, and done tests on my own cars each way, 2 of those being my own cars).
Bottom line. You have folks assuming it's fluff. I used to be one. You have folks who'd done actually used them, and stayed with them. You think if it didn't make the car better I'd want to drag around the extra weight????? Sorry, doesn't work that way. Maybe you think it's because I sell parts and a Watts link is $650 vs. $100-170 for a PHB. Well, I sell PHB's too, so that's not it (and frankly because of cost PHB's are an easier sell). I sell them because I believe in them.
The car is flat out easier to drive fast, especially on imperfect road surfaces or heavy transition. Well, race tracks tend to be more smooth, and not a lot of transition. Street driving and autox will cause you to see more imperfect pavement and of course transition from autox is much more common than road-racing, we see more transition in 30 seconds than you'd see in 15 minutes on a road course.
And to close I'll build on this. The place you'd see the LEAST difference is on a track, on a stiff car that has little suspension movement. Super stiff cars have limited travel which means less PHB arc motion. And race tracks again will tend to be in better shape overall than public roads. So for the folks who haven't tried a Watts link to say that you only need it on the track, but then it really doesn't matter anyway, I find it a bit disingenuous. Fact is they work more magic on the street than on a track, but work in both scenario's.
7x SCCA National Champion + 7x SCCA ProSolo Class Champion, 2009 SCCA ProSolo Overall Champion
I drive them, I compete in them, I sell more variety of brands than any other company.