I quite liked his Superman run. It seemed fresh:

* Superman was depicted as capable of being in genuine danger. Metallo would have killed him in the very first issue but for the intervention of Lex Luthor. Bloodsport would have shot Superman in the back of the neck with a sliver of kryptonite but for lucky intervention by Bloodsport's brother. Superman was capable of being beaten up. It was in stark contrast to the omnipotence of the character pre-Byrne.
* Clark Kent wasn't a dork: he was a big ex-football player from the mid-West who attracted women like Cat Grant.
* Cat Grant herself was a new character who was sort of a foil to Lois Lane.
* Lex Luthor's motivation to hate Superman wasn't the loss of his hair in his teens. It was driven by hubris - Superman embarrassed him by causing to be arrested and fingerprinted like some common crook. It was realistic.
* There wasn't kryptonite lurking behind every fire hydrant. There was only one shard, and Luthor had it.

Byrne's run on X-Men was actually mostly Claremont's run with some creative input from Byrne (the two ended up hating each other). I never read Byrne's Cap or Avengers other than that weird story where Scarlet Witch's kids become fiery devil hands. But yes, Byrne's FF was excellent. There was a sense of adventure which had been missing from the title for a long time.

As to the re-boot, there was a ceremony where "the Superman pen" was formally handed from I think Julius Schwartz or Curt Swan to Byrne. Maybe I read too much into that at the time, but it seemed like a real changing of the guard. Byrne is a little wrong on his analysis: many of the concepts he introduced into the Superman comic book were perpetuated: Superman was trounced by the Fearsome Five, for example, and Superman's execution of the pocket universe Kryptonians had very long-lasting repercussions including mental illness and going into exile in space (Dan Jurgens i think ran with this).

Pimping my site, again.

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