As of today, I have now watched the first 11 episodes (which means the one I watched today was Winter Wrap-Up). I'll repeat myself again, after months of imagining the audio of this show, to finally hear the real deal is a little weird at first, but I soon get used to it. It helps that I've made a habit of watching each episode three times. (I start by watching the next one first, then the previous one for what is by then the third time, then back to the next one for a second time.)
Of course, it's not all consistent; some voices are easier for me to memorize than others. Pinkie Pie and Fluttershy were close to what I had imagined, so I was quick to adjust. I was a bit off with Applejack and Rarity, but their distinctive accents are helpful enough that I can now memorize them too. I'm still working on getting Twilight Sparkle right, but I think I'm getting close by now. Rainbow Dash has been the hardest of all for me, mostly because, before actually seeing the show, I used to imagine her voice might have been like Buttercup from the Powerpuff Girls; I need to work on breaking that initial view if I'm going to memorize her actual voice. Finally, although Trixie's voice is quite different from what I had imagined, I know I've heard it somewhere before, but I can't quite put my finger on it.
And let's not forget the music. It's quite strange trying to imagine what a song is like when you've got nothing but the lyrics to go by. A good case in point is Winter Wrap-Up. The tune is quite different from what I had imagined, but I'm okay with that. In fact, that tune is going through my head as I type this, despite the fact that it's been seven hours since watching the episode, with four hours of playing Civ V within that time. Now there's a testament to this particular song's catchy-ness I've heard people talk about.
Tomorrow's episode I'll be watching is Call of the Cutie, the one that introduced us to the Cutie Mark Crusaders. I'll soon find out how far off I was with their voices.