Following the excellent article in this month's magazine, I listened to Norrington's First (on Spotify) and compared it to my Karajan version (my stand-by set) and ... enlightenment! I'm looking forward to doing the same with each of the nine in turn. Most interesting.
In similar vein, that Touch Press iPad app I mentioned elsewhere, the Beethoven Ninth one, where you can switch between four DG versions at the tap of the screen, (as the score scrolls past below and screen insets show orchestra and conductor) is similarly revealing.
I do find the technology amazing. Using something call "Air Time" I can watch the iPad screen but send the sound to the audio system, getting the benefit of superb reproduction too. Great stuff - and a wonderful learning tool.