May not fully answer the OP's question 100% but on my old E46 330d I run on the set of genuine BBS CH's I had a set of Pilot Sport tyres which when worn to around 3mm were swapped for a set of Sport Contact 3's and the change was like night and day, I discovered a better ride and it was a tad quieter inside too plus you got a decent rim protector aswell. The brand swap was quite an eye opener as the Pilot Sport tyre was as far as i was concerned considered the No1 choice. I was converted after that to Conti's.
My E92 Coupe again running 19's was something I wanted to address ASAP re ditching the Bridgestone Runflats, I found them apart from hard/noisy a bit skittish on our less than billiard table smooth roads, in fact everything I'd read from others about their overall performance was being demonstrated whenever I drove my car.
Conti Sport Contact 5P's now sit on my 19' rims and boy what a difference, perhaps the biggest compliment I can pay them is their performance in the snow, I was really impressed, plenty of feel/feedback.
I've been lucky, if that's the word as I manage the service department for an Indy BMW specialist to drive a good few E92 coupes shod with Runflats, which backs my decision to ditch them every time I drive one and the odd car which seems to be owned by a well researched enthusiast with non run flats using different tyre brands and you do register the difference, especially once the tyre pressures are correctly set, at the end of the service, but I still think the Conti's on mine, though more expensive than many other brands are worth that bit extra financially.
Re the non run flat brands I had when looking noticed were mainly Hankooks, which I can see are highly regarded after doing some reading. And there great value from the prices I've seen.