Just for the record - and this is more my paranoia speaking than anything else - I would never back up my lossless rips in the cloud. Arista used Discovery Systems for a lot of their promos, so if you have any Arista promos, handle them with extreme care! Not all discs are affected, but many are. Discovery Systems is by far the worst, from what I understand they used a very thin aluminum coating which deteriorates much quicker than other CDs and causes fuzzy distortion in the audio. Early Sony hybrid SACDs turn yellow/brown (though IIRC this doesn't affect the playability - I could be wrong). UK PDO discs bronze and eventually become unplayable. Regarding your concern about different pressing plants, that's not as big of a deal as making sure the media is in good condition.

Then I convert the WAV to FLAC outside of iTunes. I use basically the same technique as the OP, but I rip to WAV instead of AIFF and I use the lowest quality MP3 as it's going to my phone, which needs all the free space it can get.

Best lossless cd ripper