It was neat, but they were clearly streaming it live. Some framerate stutters, and once or twice in Part 1 (they stitched both parts together with just a title card for Part 2, no recap or opening title sequence) the screen pixelated significantly. I also suspect they were streaming it in 720p, the image wasn’t particularly sharp. This was likely because they had a live Q&A with the cast (minus Graham) after the episodes.
I did the same thing for the Series 6 premiere (but for that one, they did it the day Part 1 premiered, so I had to wait 2 weeks to get new content, but hey, I saw Part 2 a week early!), but that definitely wasn’t live streamed, picture quality was crystal clear all the way through - and it was fucking packed. The show has definitely fallen off in popularity in the US since Smith/Moffat…
Honestly, seeing Impossible Astronaut/Day of the Moon for the first time in a theater packed with other Whovians who were all also seeing it for the first time was such an incredible experience. This sadly paled in comparison, but it was still cool.