Rental Review - 2020 Chrysler 300S HEMI

No pics?

The 5.7L in that car is 363HP (vs the 395HP in the RAM), while the Pentastar is 292HP. 0-60 with the Pentastar is 6.3, while the HEMI manages 5.3. 1/4 mil is 13.9 @ 104Mph, so it's not a rocket ship (with the 5.7L), but is faster than your MDX, which has a 0-60 of 6.8 seconds and runs a 14.9 in the 1/4. This more realistically compares to the Pentastar.

That said, tip-in can have a big impact on how a vehicle feels and if it has been programmed to be lazy, it will feel slow, regardless of what the numbers say. I've always found that Honda has more "spirited" programming in terms of throttle tip-in, which likely explains your wife's comments.
I have to say the 6.3 0-60 with the Pentastar is eye-opening on a car in this size class. I agree on the throttle responce and shift point programming on these cars, as the target consumer is older and more in the market for American luxury with some get up and go when desired. Definitely not aggressively tuned.