ProGas vs. TurboGas Boge ?

[randrews@post.cis.smu.edu (Robert Paul Andrews)]

I am going to be buying new struts Monday for my 93 90S.  A parts house
said the ProGas were the OEM original.  But, I have also heard lots of
good things about TurboGas.  What exactly is the difference going to be?
What the feel like be between the road.  He said that the Progas were
a dual valve shock I believe and the small bumps in the city were softer
and harsher bumps were stiffer. This leads me to believe that the
TurboGas might be a little harsher in the city on smaller bumps but on the
highway, larger bumps might feel better.  Any wisdom anyone care to impart.
Thanks!
Rob