At any particular time that I was ready for tires on any of my vehicles, Michelin tires were still too expensive even if there were a $70 Rebate, which there often WAS NOT!. Although, the tires I purchaced, did have a $40 Rebate(s).
I'd love to get Michelin MXV4(Primacy, NOT Energy) if they were made in all of the sizes for all of my/our vehicles which they may or may not!
The CS4's do have a group following and the reviews seem to be very good. With either tire, there will be Pros/Cons, good and bad reviews too.
We as consumers, expect alot from Michelin and they mostly deliver.
But, since this is the subject between the two tires, and if one can get the price close to what one will find acceptable then, Michelin Primacy MXV4 is the one that I'd pick
Since I have 4 cars and, often 2 cars needing tires at the same time, I shop carefully. Because the other 2 will be needing tires soon after. I have only had Michelin tires on vehicles that came with'em and I liked them. I have never bought Michelin's aftermarket!
These days with the NET and better choices from other tire mfg's on the market such as Pirelli, (Cooper CS4), Kumho, Hankook, Altimax(s) etc., I have been quite happy with my choices without spending Michelin moneys', since I have 4 vehicles.