There are some manuals, pictures and comments about video mixers here:
We Pixelflowers have been using a WJ-AVE5 since we started. A well-known great thing about it is its time-based correction, in other words it’s a very effective buffer to have between your FX / distortion devices signals and your final output or the next step in your signal chain.
We also use an Edirol V8, which is way better as a video mixer, but the WJ-AVE5 seems to be much better at taming distorted signals and keeping them usable. The V8 just goes out of sync if we directly connect to it either a BPMC Premium Cable or a Synphonie AVE MOD 2.