CMV promoter

[Vayuputra]

Have there been any studies on the trascriptional efficiency of the CMV
promoter in mammalian cell culture experiments?  I wish to know what the
mRNA levels are (molar quantities) when CMV drives the expression of a
reporter (or any other) gene in cells.

Is it a function of the promoter in a particular cell line, or is the
efficiency independent of the cell line being used?

Thanks a lot.
Vayuputra