I went from the OEM RFTs to DWS and the first 50-100 miles I was wondering how I had made such a terrible mistake because my car felt terrible when switching lanes and turning. By terrible I mean that it felt extremely unstable and when I would quickly switch lanes it wouldn't "stick" as well and I felt like it would kind of sway back and forth. Going at high speeds also felt unstable and almost scary because going around even slight curves on the highway my car just didn't stay flat like it did with RFTs. After I increased the tire pressure to like 2-3psi above the recommended and allowed the tires to wear in a bit (~100-200 miles) they feel much better now. My dad commented today how much better the ride feels and I agree that it is smoother than with RFTs. I haven't noticed a decrease in road noise although it is probably there and I think traction has increased however that is hard to say since I bought the car with 19k on it anyways and got new tires at 23k so the tires were already quite worn. Traction is definitely good though. Overall, if you don't get RFTs and especially if you don't get PS2s then you will experience significant decrease in sidewall stiffness which will result in a worse feeling turn in and more of a feeling of body roll.
If I did it again I probably would have just replaced the rear tires with RFTs and kept the front tires until they were worn out rather than getting 4 new non-RFTs and trying to sell my non-worn out front tires. That said, I can't really say I regret my purchase of the DWS because I know they will last a long time, they have great traction in wet and dry, and as they are getting worn in they really don't feel all that bad.
If you have RFTs and you feel like you have too much body roll as it is you should NOT switch to non-RFTs because that body roll feeling will increase with the softer sidewall. However I have ridden in my friend's M3 with PS2s and they felt good so they may be an exception to this much softer sidewall rule.
'10 E90 335i | Black Sapphire Metallic | Black Dakota Leather | M Sport | Premium | Cold Weather
Cobb AP Stage 1 | Alpina B3 TCU | DCI | CF Splitters | CF Performance Spoiler | CF Trim