From that Electron remisicense:
"Also in terms of power it matched the BBC B blow for blow (until a revamp of the BBC in 1984)"
Hmm. Same RAM, half clock rate (effectively at least), no teletext chip. Like you say, very rose-tinted.
Shame about Isis. Was that the one where you were meant to be able to add extra features as modules (can't find a mention of that on the website), or am I thinking of something else?