Dueling Dubs: AnimEigo dubbed all 3 original shows (Crisis, Crash, and AD Police), but Manga UK produced their own dubs for Crash and AD Police. The original Bubblegum Crisis was picked up by a different distributor in the UK, and got to keep it's AnimEigo dub.
Fan Nickname: In 2040, "Ifursylita" and "Mackieoto" (see Expy in the main section.)
The entire voice cast (Japanese and English) changed for Tokyo 2040.
Priss's Japanese voice also changed between Crisis and Crash, due to her original being busy with her singing career.
Leon's Manga UK English voice changed between Crash and the AD Police Files prequel. His AD voice (Adam Henderson) ended up moving to Canada, and voiced roles in Inuyasha and the Ocean dub of DBZ.
Screwed By Internal Politics: After the eighth OVA episode, various disputes caused the two major studios involved with BGC, Artmic and Youmex, to split, causing the immediate cancellation of any other original-run OVAs. Who is to "blame" is debatable, but the split is what led to the franchise going Off the Rails and led to relative disasters like Crash!
What Could Have Been: Kinuko Oomori, the original voice for Priss in the OAVs, was originally contracted for the first six episodes, and her character was going to be killed off at the end of episode 6, but due to popular demand, Priss was kept alive at the last minute.
Vision's song, "Say Yes", played at the beginning of episode 7, alludes to Priss's supposed death. Vision/Reika Chan was supposed to replace Priss on the Knight Sabers.
According to some accounts, the problem wasn't that Oomori was contracted for only 6 episodes, but instead that her recording label was pitching a fit that she was singing in the OAVs in violation of what may have been an exclusivity clause in her contract (Kinuko Oomori isn't an actress, per se, instead she's a singer who's remembered for her one big role in an anime franchise, in much the same fashion as Mari Iijima) and demanded Oomori leave the series. According to this account Priss indeed was to be killed off in Episode 6, but a last-minute compromise between the label and Youmex/Artmic spared her, and Oomori was allowed to finish up the balance of planned episodes on the condition that she perform no more solo songs.
As stated above 2040 almost received a sequel series that would have been subtitled 2041 and would have featured more involvement from ADV Films, the company that dubbed and distributed 2040, but due to various corporate shenanigans the proposed sequel series never got off the ground.