E39 540iA ('00): Eibach / Dinan Anti-roll Bars

Is anyone familiar with the Dinan and/or Eibach
stabilizer bar kits for the E39?

Dinan: 28mm Fr / 17mm Rr (adjustable)
Eibach: 28mm Fr / 18mm Rr (fixed ??)

I would like to increase roll stiffness without
going to higher spring rates. The car currently
has the M-Sport suspension w/ 17" wheels (staggered
235/255). Set up this way, handling is neutral on
fast sweepers but can get down to the bump stops.
Tight slow corners bring out mild understeer (which
can be addressed somewhat with throttle).

What reasons are there to choose one make of aftermarket
bars over the other (besides price)?

How is the fit, finish, quality of the product you chose?

Where did you get your bars and how much did you pay?