I would say so. Even the Sport SLKs only came with 17's... Big difference in dampening forces needed to keep a 19" 36-pound wheel in check.

This thread is a great read on the subject:

Recommend shocks for my C32 - HR Lowered - MBWorld.org Forums

Konis have the adjustable fun-factor, but the Bilsteins seem to offer a better bang-per-buck and one guy even swapped his Konis FOR Bilstein...

I've considered the B shocks as well, and thought about getting the SLK version since I'm running so low. But I hadn't thought about the lack of dampening for the 19" wheels until just now...

Hmmmm