Alicornutopia

This is a spoiler.

obviously most of the characters have been gender swapped, with some exceptions.

The Volturi haven't been, but they did have a big change. Aro was killed and his wife pretty much took over. Marcus is actually the only guy left standing.

Renee, Phil and Charlie are still the same gender.

The ending. Yeah sooo different. Turns out Beau (Bella) managed to excape from Archie (Alice) and Jessamine (Jasper) five minutes earlier than Bella did, resulting in him becoming a vampire. Edythe (Edward) was unable to suck the venom out in time

Archies visions work a little better.

There are more differences but those are the ones I can think of right now.

There are a few other characters who are the same gender, but so far they get little-to-no page time. It’s still Mr. Newton who owns the sporting goods store, and it was still a girl who dropped a note off with the secretary on Beau’s first day.

Generally more scenes or other details are added, and some other details are changed or corrected. For example, Renée leaves Beau at TSA instead of the pane (a correction, given that the story is set in 2005), and some more of Beau’s thought process is written.

Beau’s personality is slightly different than Bella’s. This hasn’t really shown up much yet for me, but it’s a bit so far and I expect to get somewhat more visible as time goes on.

The author’s notes at the beginning say that Archie’s visions are also more consistent than Alice’s, not just better.