Well, considering that the stock system limits the boost if it hits around 14 psi, and Mercedes tended to be nervous Nellies, I'm perfectly comfortable with 12, which is allegedly stock anyway. I've never seen one that still did 12 with everything original though. I had to turn mine up with a boost controller to get it back there. Clearly the "everything breaks" limit is well beyond 14 psi. I've yet to see anyone report a problem with going higher.

Plenty of "thoughts and feelings" though.

-Rog