In my experience they are good quality and reliable boards and probably cheaper than the alternatives. I'd definately recommend it if you don't already have a video card in your A4000.
Radeon grahpics cards won't work in the 4000Di at the moment but Elbox are planning to produce an adapter with an auxillary 3.3v power supply, so get in contact with them about that one.
If you can find a cheap PCI Voodoo 3 then it is probably worth getting a Mediator while the shipping is free.
