If a toy has less than 50% of its parts being the same as a previous toy, I usually refer to them as "new with some reused parts" ... as I imagine that the computer program they use these days, has pre-existing parts in it's library, like lego bricks, to re-use without having to create them from scratch (and saves them from creating new toolings).
I only recently got the Generations Big Powered boxset, and Sonic Bomber (the black jet) is noted
on TFWiki as being a retool of Misfire, but just like Ectotron, it only shares some minor parts (arms and thighs). Even the other two may have started out using Skyshadow and Twintwist, but the massive amount of alterations only barely makes them a heavy retool (any more and they'd be "new with reused parts" ).
Since Combiner Wars, it's been a new addition to my personal scale of new-to-redeco status of new toys. Just looking at this year's checklist, it looks like I have Galaxy Upgrade Optimus noted as that, as there are more new parts than reused parts.
