I can vouch for this as well. I had a set of KYB Gas-A-Justs on my fastback and while they gave pretty decent body control, they rode terrible on rough pavement. They were so bad that the back end would slide out if I hit a bump mid-corner; they just couldn't keep the tires on the pavement.

I switched to a set of Edelbrock IAS shocks (got them for cheap from a friend) and never looked back. The only reason I don't recommend the Edelbrocks is because the Bilsteins are only a few dollars more.

 

My experience was mostly the same with the KYB's. They handle decent for the cost, but on rough roads didn't do so hot. And the ride quality was never that great, but the roads round here suck dick pretty hard.

The reason I recommend the Bilsteins from Maier is that they've spent 30+ years working on the valving for the Classics. Bilstein offers tons of factory valving parts so you can custom valve shocks, which makes them popular in racing crowds. The Maier shocks are a custom valving for the Classics for the spring rates you run. It's the closest thing you can get to a modern high performance factory engineered shock for our cars, and the culmination of decades of trial and error and track/street use. It's pretty damn evolved.

They do have a newer, better shock available in their coilover kit; from a company run by a former top shock guru from Penske (Penske shocks are absurdly expensive, with a set of 4 typically running into the thousands).