Hi,
A favorite of mines has always been Native Instrument's VariComp. This compressor/limiter simulates a Manley Variable Mu device, an improved version of the glorious Fairchild 660/670 often found in the old recording studios specialized in classical music.
A beautiful feature of this plugin is that you can choose to make it either transparent or tubey-fat, depending on the level of the input. The ease of making parallel compression is another favorite of mines.
The Compressor Pro and Limiter Pro included in VEP7 (and Vienna Suite) are however much more transparent tools. Compressor has a Fat option, making the sound bigger (by apparently increasing the low frequency content), but with not perceivable distortion.
Not only that, but I find that the VSL preserves the natural depth and details of the original sound, while the VariComp doesn't. Even with the most transparent settings, low-volume sounds like the bow touching the strings disappears; with the VSL, it is still there, and the result is increased realism and depth.
At the same time, in some cases one can prefer the fatter, less 'honest' image offered by the VariComp, if that is the type of sound one is after.
You can check yourself in these two versions of the same piece, starting from the same original. No Exciter used – the VSL image is airier by itself.
Holst on VSL Compressor Pro and Limiter Pro
Paolo