Are there any companies that have bags or air shocks that are made strictly for comfort and keeping roughly the original height?

Am I correct in that you use an air shock in the front and bags in the rear?

Also, I would imagine that the compressor is super critical in that it is constantly working when moving. Also, do all compressors take a fair amount of time to raise or are some quicker than others?

xfireon20z, what brand are you using and are you using all airbags or all air shocks or..?

Aren't there any Mercedes models that have a similar type suspension but with air suspension so that one could go semi-OEM - and possibly find a used set?

I am glad to hear that it isn't all that rare to go with air suspensions on their XF's. I'd sure like to take a ride in one that is only slightly slammed.