I have an A4000T with Mediator, Radeon 9200, Sb128, SpiderII, RTL8029 & Sii3114 for SATA drives. My setup dual boots OS 3.x and 4.1. Video is great: fast, high res (1920x1080), and sharp -- in OS 3.x I get the extra RAM as system memory. Sound is great (OS 4.1 AHI on SB128 is good). RTL8029 is supported by both OS, but a USB NIC dongle is much faster. Spider works fine in 3.x (4.1 does not support it due to DMA so I also have a Deneb). The Sii3114 is only supported in OS 4.1.
Please note that OS 4.1 wrote their own drivers for the Mediator, so the support list is different. OS 4.1 doesn't use much of the Radeon RAM and even then only for graphics.
Overall: it makes your system a more modern machine for the current cost of a Picasso IV. Elbox offers only "squeaky wheel" support and you have to be patient, "squeak" constantly, and be prepared to have them ignore you. Either get your Radeon card from them or Amigakit. You can use a hacked NEC USB card if you want; you will find a ton of user help ( because there is so little from Elbox), and with OS 4.1 it makes you feel like you are using a modern machine with the ease of an an Amiga
