I am always concerned about migrating information so I store all my files on dropbox to transfer them over. I have used the migration assistant, but I spent half a day making sure everything is okay and I also chose not to migrate some things. I think a few hours is more than enough, depending on internet connection and the amount of data, but my old laptop had a near dead battery and it took a while. I did actually decided not to import my photos and iTunes which I now regret. What are the best ways to migrate large files quickly?
There isn't. Data transfer will always take a while due to the read and write speeds of modern hard drives. Of course, Solid State Drives will make it a bit easier; however, they're an expensive option for a temporary problem. I say just go do something else while your files are migrating. If you're talking about storing in the cloud, then you're also limited by your upload and download speeds. In the end, just get an external drive and stick all your important files on there when you get a new computer. Cloud backups take too long and transferring your entire hard drive is a waste of time.