To be perfectly honest, this movie just summarized all the best parts of the original SAO that I enjoyed so much before the Aincrad arc got rushed into its completion, so of course I'm inclined to like it. But it really doesn't include a whole lot of new content. So the real test on whether SAO Progressive is the best way to watch this Anime will come with the release of the second movie, and I eagerly await it. If it's as good as I'm hoping, I'll probably just recommend people skip the original Anime and watch Progressive then they can watch the series at their own risk.
I will give this film a 7/10, but it's a non canon story that diverge from the light novel and the original anime
There's not much difference from season 1, but there are some things that are explained in more detail here.
Shout by Supriyo GhoshBlockedParent2022-07-11T18:20:49Z
First half of Season 1 of the main series (https://trakt.tv/shows/sword-art-online) with extra details to the plot from Asuna's perspective.
Nothing extraordinary, if you've watched the anime series.