Dunlop SP Sport Maxx ROF

Let me first say that I understand all the arguments for and against run flat tyres, but I simply can't get on with the harsh ride and cost of replacements. I have just done 21,000 miles, being a mix of country, motor and town driving, on 275/30/R20 Dunlop Sport Max GT ROF fitted to the rear of my BMW 640D MSport. At 2.5mm on the rear nearside, the car was telling me I need new tyres; bit of wheel spin and tail end is a little happier than it used to be on round-abouts in the wet. The front 245/35/R20 still have 5.5mm. I would not say that I am spirited driver, but given some space I do like to push the car a little. In terms of wear, I would say that the Dunlops are reasonable; I used to get around 20,000 (based on 3 sets) out of a rear set of Eagle F1 Asymmetric 2s 255/30/R19 fitted to a BMW 330D MSport (mapped to 265bhp with 571nm). What I didn't like about the Dunlops was the ride, the jarring of my jaw at every pot hole and the rear end skipping ever time you hit a bump on a bend; just like the ride I used to get with Bridgestone Potenza RE050A ROF that were fitted originally to the 330D. So you would think the obvious choice of replacement tyres for the 640D, given my history, was the new Goodyear Eagle F1 Asymmetric 3, but disappointingly neither the 275/30/20 or the 245/35/20 are available except as a "run flat" - aaaaaargh! Instead I have just fitted the new Continental Sport Contact 6; TyreReviews video helped enormously with the choice (you don't get so much feel in a 640D, so went on the basis of slightly better grip of the Continental over the Michelin) and CAMSKILL sealed it with a very competitive price for the Continentals. I was tempted to replace all 4 corners, but there some reviews of the Contact 6 suggesting that they do not wear particularly well (on that basis I may as well get the remaining wear out of the front and then replace all 4 at a later date). I have only just fitted the Contact 6, so a review on them will follow in a month or two.