Hi Josh,
wish you a good house hunting :-)
Meanwhile I'll try to give my help. I replayed the same playoffs I played with the previous setup so that I can make some kind of comparison. I know it's not a big sample, but better than nothing.
- the "65/85 autosubs" has some peculiar traits: CPU running game extremely good and cpu AI is better than my AI (this is clear in pass coverage where my pass coverage is extremely static, even worse in zone coverage, while CPU's is quite good). You can consider it a boost on CPU, I suppose due to the fact that we set autosubus only for our team.
This helps the CPU QB: he's quiter, he waits in the pocket, makes good choices. He's completion percentage is pretty high, even if I still get many picks: I wouldn't say it's wideopen-or-pick, but you get that feeling.
I'm assuming my passing defense would fall pretty low on stats if I play a full season with this setting.
- the "slow on MM" setting is different: coverage is very good on both sides and this makes things tougher for the CPU QB. Despite of this, defensive animations are pretty good, without "superman DB", so INTs are good. I'd say the CPU passing game is more realistic, but less effective.
CPU running game is so-and-so, for sure worse than the other setting: despite rock-blocking (I can't manually block shed with a 88 BSH MLB) the CPU hb doesn't hit the holes properly and sometimes slows down with open field ahead. It looks like he's waiting for the defensiveman to approach.
So, to summarize: the "autosubs" setting is for sure more challenging, I'm pretty sure I would be in troubles to play a season, but looking it play-by-play it's irritating to see my pass coverage not covering.
The "slow" setting is more organic, but the CPU is extremely cautious, probably too much, making the final result quite obvious, most of all for my team which is very good in running game: I'm pretty much sure I'd go for a perfect season with this setting.
I'll play the first few games of the new season with the slow setting, lowering the injury on CFM step by step and see.
I am also curious to understand if there is some kind of home field advantage, I couldn't find it in M19 lately and it's a shame.