Cube-DCFanBoy,
Here is one my thought. Download a benchmark such as SPECViewPerf v6.1.2. Run it on the Geforce card you are going to SoftQuadro to set a baseline. Then, do the SoftQuadro operation and then run the Benchmarks again. Now, you will be able to see the diffence exactly on your system. Also, you will be able to compare with others to see if you are on the mark.
SPECViewPerf v6.1.2 has a number on benchmarks. If you are worried about Maya 4 performance, use the "AWadvs-04." This simulates Alias/Wavefront types of applications. The others are not bad either.
If you go to http://www.nvidia.com and look at the quadro line of workstation boards. You will be able to find some SPECViewPerf v6.1.2 benchmarks for thier products.
Does that help? I hope so!
I have one thought to throw out to all, Do you think it would not make much differenct whether I would use a Geforce 3 Ti200 or Ti500 to become a SoftQuadro "Quadro DCC" card??? The reason I ask is, that a Geforce 3 Ti200 is about $150 and a Ti500 is about $300. According to Tom's Hardware Gude, the Geforce 3 Ti200 had a base score of 75 and 100 for the Ti500 (in a round up article).
I want a card that will work very well with Maya 4, but without going crazy! But, if for $150 it does not make much of a difference, I do not want to throw money away.
Also, I realize that the Quadro DCC can be bought for about $750, so regardless I am still ahead. But, if Maya 4 is so demanding, then I would not want to waste $150 for Ti200 when the $300 Ti500 woud be right!!!
Do I sound like a mad man or what???? 
Any thoughts?
Thanks!
--Sir Gareth