I just used it UA 893 (SFO-INC) on 8/15, and UA 892 (INC-SFO) just now--both full 747s, but I didn't walk around to see who else might have been using it.

It worked pretty well on the first trip, though a I noted a little buffering on my iPad. Interestingly there was a lot of buffering on my Macbook when I tried that. Coming back just now it worked perfectly, no buffering ever, on my iPad, I didn't try the laptop.

One small caveat, the feed shuts down before landing, as compared to regular IFE that keeps going clear until touchdown and taxiing.

Overall, ^^ from me.