The basic plot of this episode, about Tuxedo Mask revealing to the nation that he is looking for the Silver Crystal, comes from Act 6 of the manga. It was never used in the anime. A crucial scene in this episode, Mamoru's recurring dream about a girl asking him to find the Silver Crystal, is also from Act 6 of the manga, and appeared in the anime in Episode 26. Mamoru explains to Usagi why he is searching for the Silver Crystal in Act 7 of the manga, but his explanation is much more detailed than the one he gives in this episode of PGSM.

The rest of the episode mostly consists of embellishment of the rather thin "news" plot from Act 6 of the manga. For example, the whole thing about Ami going to the guy's house, and Usagi and Makoto going undercover, and the fake Tuxedo Masks... none of it came from the manga. Also, the suspicion that Tuxedo Mask is the enemy continues to be emphasised much more than it was in the manga, with the other Sailor Guardians quite annoyed that Usagi seems to have strong feelings for him, and that she continues to trust him. In a way all this is a good thing, because it made for quite an amusing episode (even if it wasn't one of the best episodes so far).

On the other hand, the manga chapter had the heart ripped out of it in a sense - it began with the revelations about the Moon Kingdom that come in the next episode of PGSM, and it ended with Usagi discovering Mamoru's identity. None of that happens in this episode of PGSM. Also there was a battle with Sailor Moon alongside Tuxedo Mask, where Sailor Moon used the Moon Stick for the first time (in PGSM, of course, she got it right at the beginning of the series).

With a few exceptions, this episode is a small subplot stretched into a full episode. PGSM's plot structure means there are still plenty of important plot points in it, though.

To comment on some other things: Jadeite is still out cold after the last episode, and Queen Beryl turns him into a gemstone (presumably a Jadeite stone) so that he can preserve his energy. The implication is that he will be back at a later stage... and I hope he is, because if the end of Act 8 was his final battle, it was a bit anticlimactic. Of course, all of this is original to PGSM - he was gone long ago in manga and anime.

Finally, although I didn't think it warranted mention in the "Important Events" section, I think Ami's behaviour in this episode is somewhat noteworthy. She observes Rei's anxiousness and bails her out of a situation she obviously doesn't want to be in, and and she lets Usagi hug her when everyone else is being mean. It's subtle, but she's certainly come a long way from the Ami of episode 2.