might even be worth the cost increment to use it in one or two public rooms but probably won't even be noticed by any but the really informed/experienced.
Yeah, for sure. I doubt most homeowners would ever tell what kind of paint you used. I think paint type is more for the pro - it's he who determines that attributes of the paint he's willing to pay for, how many coats it will take, how it applies, how he deals with that paint company, their color line or how they match color, etc etc.
If the paint gets on the wall correctly, no one will ever know more than that (remember, you can put on the same final thickness of any paint you want depending on how many coats or how you apply it). There might be some uncommon circumstances, such as Cashmere appearing a bit more smooth, or something like that.