Mitch, Macs using iTunes don't rip to flac, although they can if one uses other software. Downloads in flac are no problem. I have a few albums transferred in wav, but the vast majority are in aiff, which is similar to wav in that it is not compressed. If you go back and look at the earlier posts, you will be reminded that I found with a sampling of albums, wav sounded subtly better than ALAC. Based on this finding, coupled with a few trials in which I could not distinguish between aiff and wav, I decided to commit to aiff, which usually transfers without corruption as opposed to wav, which was a nightmare of corruption. I did work out a laborious protocol for using wav and maintaining it in uncorrupted form once it is transferred, but since I can't discern between wav and aiff, I'm not motivated to use it at this point.
With almost 800 albums transferred, I still have slightly more than one half of the internal hard drive space free. Clearly, I could transfer the remainder of my library without using an external drive. An additional comment that I would make is that with most albums, I could not discern a difference between wav, ALAC, and aiff. However, since HD space is not limiting, I just went with transferring uncompressed files rather than sorting out which ones would benefit.
Once the bulk of the library is transferred, I want to identify my first and second choices for classical works, then either transfer the 3rd, 4th, and sometimes 5th choices of a particular work to an external drive as well as some works that very rarely get a listen (Sorry Elliot Carter, but you have had your chance-time to show you the way to the external drive.) That way, I should always have room for additional acquisitions to the library on the internal drive.
Another thing I am noticing is that using the album view for selecting music is becoming somewhat cumbersome. Between, Bach, Bartok, Barber, Beethoven, Bernstein, Brahms, and Britten, it takes a while just to swipe through the B's, and I have nowhere near all of my Bach and Beethoven loaded yet. However, this is nowhere near the problem of trying to find or even remember that I have certain albums in hard media (still can't find that Abaddo Mahler 1). I am going to go through the titles and be more specific on genre, which will help me get to a given work more quickly. For instance, there is no reason why I can't define genre more narrowly, for instance, using Lieder, rather than classical, as the genre for my beloved Schubert Lieder, which will allow me to quickly access the music without swiping all the way to the S's in the album view. I am avoiding use of the favorites flag. Too tempting to have my library effectively reduced to 100 titles! Also, I am finding that some recordings I avoided because of bad sound demand a reassessment. But these are subtleties that can wait for an opportune time.