have you tried BC racing coil overs and are they comparable to KW

I have put Arnott's standard shocks and springs on my SL55 and as well as on my son's E500. The ride is still great, like having it on 'sport' mode. They sit high to begin with bit gradually lower down after a couple of hundred km. I will be using them for my SL55 when it decides to do the droop.

So your son is using bc racing and you are using arnotts
Sorry didn't completely understand.

Everyone is telling me bc racing is very bad kw is much better and most of the comments are air matic is the best but I fixed it many timesfrom pump to struts and honestly I developed a phobia and now pump is weak and I hear hissing sound when I unlock the car

Look at the price difference between the two, there will be a difference in ride and quality. However it all depends what you are looking for in your car, better handling? Comfort without breaking? Many people have done the BC coilover swap, usual feedback is it rides well enough with better cornering.

What IAM looking for with priority in order
1 peace of mind of not braking
2 comfortable ride
3 performance enhancement

I would go for the Arnott kit personally if I was in the same position. KW is definitely your best option for performance but the V2, V3 (if they make them for E-class) are quite expensive and probably not worth it.

Kw v2 is double bc exactly
Arnotts I can't find good shipping

I have BC for 3 years now in stock high. After few weeks the car sit about 1" lower.
The only problem I have is my pano-roof rattle a bit when I go over uneven places. If u have pano-roof, i dont recommend.
Not sure if the same with other Coilover but I assume about the same.

My setting is 15 click front and 20 click rear. (total 30 clicks)

Is there coil overs as comfortable as oem airmatic ride ?