As it was allready said If you want to avoid the use of a monitorswitch go for thr CV64. Though a PIV is an option too, but as long as you don`t plan to use one of the PIV extramodules it`s a waste of money, as the Performance is just about equal and the A3000 allready has a scandoubler.
I won`t expect much in terms of 3D performance from the CV3D. The active support for the card in Warp3D stopped somewhere along the way, meaning the existing driver simply wasn`t updated from a certain point on.
On my CSPPC 060/200 System Heretic II was faster in softwarerender then in hardwarerender with the CV3D back then, though it looked better then in softwarerendering.
There might be a small performance bump with GLQuake or the special Version of Descent (no, not Freespace, the old thing from the stoneage) for the Virgechip.