Think of a race only application where you have different track conditions. Especially as in road course circuits. Even on a street car it's much easier to get to. It's not necessarily the "how much" they might need adjustment, but just the fact the adjustment is "right there" where you can adjust as needed on the fly, instead of having to get out, open the hood, blah blah blah......
That's just where I've always put them. You can put it anywhere you want. On the 51 Chevy truck build I did for Matt, one came with the M/C and it mounted directly under the driver's seat. When we got it where it was driving, we had to bring it in, stick it on the lift, let it up, adjust it, let it back down, drive it rinse ans repeat until we got it just right. If the valve is where you can get right to it, it's a lot faster to get it adjusted right.
