The reason I skipped it is addressed in an earlier comment: there was no code transition. The 65C816 ran 6502 code natively. Yes there was a bit of native code, but if Apple had run the CPU at full speed, and devoted real effort to the IIGS, it would have killed the Mac off. It is, sadly, for the best that they didn't.
I speak as someone who never owned or used an Apple ][. I was born in Britain. When the Apple ][ was new, it cost as much as a car in Europe. My first and second computers were Sinclairs, and my 3rd was an Amstrad (who bought Sinclair).
The Apple ][ may have been the first home computer under US$1000 but in the UK that was a very large amount of money. Sinclair made the first home computers for under GBP 100, a far more important cost barrier for us.