No experience with any of those. Elf Audio also has the Arc Mini amplifier boards. They only have the 2-channel on their site but I believe they offer all 3 models. There was a long debate on DIYMA about whether or not they used inferior parts to their Arc counterparts. At one point someone owned them both and posted internal shots of both amps, although I honestly can't remember the results. Moral of the story is that I'd expect the Elf and the Vibe to be similar.....so if the Elf used lesser quality parts than the Arc's, I'd expect the same from Vibe.....and if you can find the Elf's for less than the Vibe's, that could be another option for you as well. Another option would be the new Zed line, one each of the Leviathan and Kronos. Fits in your budget and you'd have 10-channels of high power amplification in just 2 reasonably sized chassis. Or if you really wanted flexibility go with two Leviathans. That'd give you 12 channels to play with, but it'd basically hit the cap on your budget.