It's fairly decent, but it's not a retargetable graphics card. It's a frame capture, genlock, primitive switcher, picture in picture, flicker fixer type card. You can use it with EGS (GVP's 24-bit graphics library + workbench like clone) but it's not useful for non-EGS software.
This card won't help you if: "I just want pretty icons and a nice 3.9 desktop" . It's closer to a Video Toaster then a Cybervision card. It's also a Zorro II card so it might not be the best thing to use with your A3000.
The EGS Spectrum, Retina ZIII, CyberVisions (64 and 64/3D), Picasso IV are probably much closer to what you'll need.