I used to have an A4000 with CyberstormPPC and a CybervisionPPC (Ok, still have her.. In several pieces)
The CVPPC is a good card, even considering it's age, tho you may have some trouble putting it inside your A4000 (Then again, since it's a T model, maybe not).
It gives a good display, with high resolution with a good refresh rate depending on the monitor used. It's also pretty easy to adjust the refresh rates and screenmodes yourself (I don't mean setting the screenmode in the preferences, I mean making your own screenmode.. If you want a 660*540 or something screenmode, then you can try to make it with the software provided), tho I'm not certain wheter this is because of CyberGFX, or the chipset...
On the negative side, only supported by CyberGFX, no P96 drivers (AFAIK), and no default pass through, and the one made by P5 isn't all that good, IMHO..
Anyway, I never regretted buying one...
