Justin is buying a new 5K iMac. How does he migrate his old data into his new machine? Leo says that there is a migration tool built into the iMac to move it over, but if he doesn't want to move all of it, the migration tool will allow him to move just the apps. He should let it do that because it'll do a better job.
Leo says the best way to do it is to just reinstall it all natively, though. That way he won't be moving over the old kruft. He can just go to the App Store and re-download his apps to install them. It's really the best way to do it. Also, with the new macOS High Sierra, a lot of older apps have been broken, so he'll need to download the apps anyway. ArsTechnica has an article on it here.
Leo also advises against getting a Fusion drive. He should go with the SSD. APFS doesn't work with Fusion drives.