I have both the CLS 501 dichroic color head and the VLS 501 dichroic VCCE head.
Perhaps you should check out the VLS 501 head. It is identical to the CLS 501 head (ergo it has the same fan making the same noise, has the same two magenta and yellow filters (!), etc.) but has the very nice advantage of having only one dial for contrast and thats it. Dial in from 0 - 5, and you get the contrast you want (obviously you should test it with your papers so you know what scale means for that particular paper.)
Unlike other VCCE heads, the VLS 501 is not cold cathode, it doesn't have any weird special lamps, doesn't require a special power supply, and still keeps exposure constant throughout the contrast range. It does this by simply dialing in and out the apropriate amount of magenta and yellow filters, and blocking the amount of light coming through dependant upon the amount of filtration dialed in (no filtration ("2.5" on the scale) means the light is reduced, full filtration means the light is leth through at full). Its a completely mechanical system. The light source is the same as with all of the CLS heads (250W ELC lamp).
Its a very simple system, with the advantages of a difuse light source, the easy of use of a VCCE setup, but without the cost and complexity of proprietary controlled and metered lamphouses and the ensuing electronic nightmares that come with them.
Ofcourse, if you really like condensors then obviously the VLS 501 won't be what you're looking for.
-Z