Time to give my late, precious and unrequested opinion on the previous and next episode.
I know jackshit about Naruto and Bleach, but afaik this match up has been requested since a long time, and both characters seem to be fascinating.
I can't judge how good or bad the ratings and the result are, although feats and reasons seem to make sense at a first glance, at least.
The bigger complain I've seen is that Aizen is apparently already resistant to attacks that destroy the soul, and this wasn't addressed in the episode.
Still, the fight was pretty good imho.
Both seem to be those kind of characters who can do a hell lot of things, and it was interesting to see all their exotic attacks and powers interact, like the Susanoo and clones clashing with the dragons, or that spirit thing protecting Madara from Aizen's black box.
I also found the drawing of white Madara (the shot you see when he emerges from the dust) really good.
Another peak sceen was them laughing maniacally at each other, fun and fitting, if that's in-character for them.
Lastly, even their illusion exchanges was interesting, they actually had me at first, when they showed Madara being vaporized.
About Saitama vs Popeye, it's a big let down for me.
I appreciate using a niche character as Popeye for the end of the season, and It's also the chance to learn something about a classic character.
On the other hand, using Saitama is just a big mistake.
Simply put, we don't know Saitama's limits nor the full extent of his capabilities, thus using him leaves too much room for speculation and arbitrary distinctions.
Iirc they also said the same thing in a past DB cast, but apparently they have changed their mind.
If they're going to take Popeye's sun feat as legit, I guess they're also going to use the OPM infobook which states that Boros' cannon can annihilate stars.