I have raced for about 15 years now and I've owned bikes made by two other custom builders.  Two things stand out about Sachs frames. 

First, the workmanship is flawless.  These bikes are made by somebody who really sweats the details.  Second—and most importantly—nothing I've ever ridden rides like a Sachs.  These bikes are incredibly comfortable.  The fork soaks up road shock like a Rock Shox. 

What really sets the bike apart is the way it handles on a fast descent.  Even at 50+ mph the bike is amazingly stable, almost like you're riding on a rail. 

I liked my Sachs so much that I bought a used one for a second bike.  It was built in the early 1980s and it still rides great.  I don't think many other bikes on the market today will be ridden for 20 years.  The only bad thing about owning a Sachs is that you don't have any reason to buy another new bike.
 

Robert Bell with a Texan.  We're pretty sure Robert is the guy on the right.