I think what joemikeb was responding to here is that MikeS asked what if he was in the process of migrating, and changed his mind about his migration strategy. My reading of it is that joemikeb was saying rather than quit the migration process, which could muck up some things, just let it finish and then just start over by erasing the mini and doing a clean install.
You nailed it. Stopping the migration process would leave the drive you are migrating
to in an unknown condition so it is preferable to erase the drive you are migrating to and start all over from scratch rather than deal with who knows what.
Joe, you say "FWIW Leopard broke more Tiger stuff..." This is, well, appalling, is it not? Both OSs from Apple yet the newer one broke the older one? No wonder I never upgraded from Tiger, then, it works fine!
Those of us who have been with OS X since the Public Beta have always been aware OS X has been a work in process from the very beginning.
The overall structure of OS X consists of multiple layers supporting one another. Tiger pretty well established the user interface layer of OS X. Leopard's changes were a level deeper and added substantial new functionalities as well as moving OS X to what is likely the final API (Application Program Interface) structure where apps tie into the OS to receive services. A lot of earlier APIs that had been deprecated were dropped while others were changed or the functionality moved to another API and still others were added. Some of the new functionalities introduced significant additions to the volume structures on the hard drives. These changes were announced and planned well in advance, but no few application developers chose to wait on making the necessary adjustments in their code. As a result a lot of applications, utilities, drivers,
etc. were broken by Leopard or in some cases could break Leopard.
The changes in Snow Leopard may well be the most drastic and dramatic so far, but the vast bulk of those changes are at a still deeper level, way down in the guts of the OS itself and any changes in the APIs,
etc. that effect application functionality are relatively few and relatively minor. In effect the applications are all floating above the dramatic structural changes in Snow Leopard and are therefore relatively unaffected.
So it was not surprising to me that Leopard broke a lot of things while Snow Leopard broke relatively few and some of those because the application developer took advantage and "hung" some of their code in places they shouldn't have. I will say in the application developer's defense, working on the Windows platform they have four, five or more years to prepare for a new Windows release. Working on the Mac platform they have had learn how to adapt to an eighteen month OS release cycle and that is not a lot of lead time. That eighteen month release cycle is considered a major strength of OS X allowing it to rapidly adapt to a market demand that is continually and rapidly evolving.
