Wrapped up our rewatch of the MISSION IMPOSSIBLE films last night and wanted to record a few quick impressions, if only for myself:

FALLOUT is by far my favorite of the series. Were they going for the Tom Cruise running scene to end all Tom Cruise running scenes? If so, they achieved it.
Henry Cavill needs to play a villain more often. A hook-headed, face-melted mustachioed return would not be unwelcome.
I appreciated the M:I II rock-climbing callback, minus the Woo-doves and Limp Bizkit.
Even though we rewatched ROGUE NATION a few weeks ago, I still don't remember anything – save it being Rebecca Ferguson's debut in the franchise – about ROGUE NATION. Was that the one where he jumped on the plane?
I still have a soft spot for M:I III. Philip Seymour Hoffman was a spectacular villain and the addition of Michelle Monaghan’s Julia added much-needed personal stakes and tragedy to the entire series.
I wish that Renner had been given more to do, a failed attempt at legacy, like BOURNE LEGACY.
I also wish that Brad Bird had directed more than one film in the franchise - though Christopher McQuarrie's ongoing spin on it has been truly spectacular.
Since 7-8 are supposed to be the swan songs for Cruise's Ethan Hunt, maybe 8 could be the LOGAN / DARK KNIGHT / NO TIME TO DIE for the character, a future-set thing. I don't know, given that Hunt seems to come back into the fold in every installment anyhow. Might be neat, given that, by the time 8 arrives, Cruise will have played the same character for almost 30 years – I can't think of another actor who has done the same (though one could argue that Chaplin played The Tramp for the entirety of his career).
Rebecca Ferguson should take over the franchise for any installments following 8.

Should anything else spring to mind, I'll add it here.