Eyetech have their 'industrial' market, BPlan/Genesi have the PPC Linux market. OS4 & Morphos are spinoffs really.
From what I've read both are/will be equally capable of replacing a classic system (at higher speed, with more memory ;-)), which is what I'm looking for personally.
As for which one I fancy getting ... I honestly can't decide, though at the mo Pegasos is a little ahead because of the price, and the extra clock speed of their G4 lends itsself to running UAE a bit better than the uA1 (and the XC seems to still be a good way off).
As for weather they're real Amigas, no, of course not, they're a replacement for them. I suspect those that complain about the lack of custom chips only play old games on their Classics anyway.