'Transfer info to this Mac' vs 'migration assistant'

The_Knowledge_Seeker wrote:

What's the difference between selecting 'Transfer information to this Mac' (via a Time Machine backup) and running Migration Assistant instead?

I'm specifically thinking about a macOS Time Machine backup (macOS 10.10) being restored to a new Mac running macOS 10.15. Does macOS 10.15 on the new Mac get overwritten by the macOS 10.10 backup?

One use the an external Time Machine drive, the other uses the internal Mac drive.

If the TM is up to date it is exactly the same thing...

The most trouble free way to move to a new machine, is using the Setup Assistant on the initial boot— you have one shot here. https://support.apple.com/en-us/HT205749

If that opportunity has past, the second best way is use the Migration Assistant.

How to move your content to a new Mac https://support.apple.com/en-us/HT204350

Your mac is not going to revert to a previous macOS. You are transferring your user information to your new Mac...

not restore.

The_Knowledge_Seeker wrote:

In that case I guess I'd want to erase the Internal (macOS 10.15) drive completely then restore in full from the time machine backup (macOS 10.10) so the result is that the new Mac will be running macOS 10.10.

What about the situation where the old macOS 10.10 Mac is running applications that are not compatible with macOS 10.15 (such as 32-bit applications)?

Does that sound reasonable?

No. You really seem to be struggling here.

Your mac is not going to revert to a previous macOS.

If the app are not compatible it will not run them.

With the release of macOS 10.15 Catalina, applications will have to be 64-bit.

Update your software

App developers will issue updated apps if they want their apps to work on this newest macOS upgrade.

32-bit app compatibility with macOS... - Apple Support

https://support.apple.com/en-us/HT208436

Buying a new machine is about moving forward not backwards.

It never pays to get too far behind in the software or hardware, it only makes it more difficult to make a graceful transition.

It is essentially the same thing, with two small differences:

1) One is at the time of installing, the other at a subsequent time

2) In the first case, you do not have to create an account, and can have only the accounts that are transferring; otherwise, you need first to create one (admin) account, login, and then (or later) run Migration Assistant.

You should also take into consideration that this new account you create should not have a name that conflicts with the ones you want to migrate.

For example, say you have a TM backup of your old mac and are starting a new mac you just bought.

Your old mac had two accounts, say "me" and "wife".

You can start your new mac, choose to transfer "from another mac, disk or time machine backup", and have the two accounts ready to use, with all the photos, mail, settings....

You can start your new mac, choose not to transfer anything: you will have to create an account, ...

and then later, if you like, use Migration Assistant to bring back the stuff from your old mac.

Either when you transfer on install, or when you use Migration Assistant, you are given a choice of what to transfer.

It used to be that installing all the applications was a pain, but no longer.

On the other hand, if we keep transferring everything it will come a time, sooner or later, when some of the stuff no longer works, and can even cause your system to break.

That is why, when installing on a new mac, or upgrading to a full new OS (like Mojave->Catalina, or Catalina->Big Sur) I recommend to transfer or migrate ONLY the user accounts.

Applications can be redownloaded from the App Store, or the developers sites.

Stuff like extensions or launch agents that may have been there and forgotten will silently fall by the wayside, as it should be, and the things you do use will be installed fresh and up to date.