OK just fitted these to the car today so thought I'd give my first impressions after a 6 mile hoon round the county roads where I live.
In reading this you must bear in mind that its a balmy 14 deg here today (so well outwith the optimal temperature range for these tyres) and that they are fresh out of the packet with no bedding in at all.
On pulling out of my street it was clear that these have a slightly vauge feeling compared to the PS3's I've just taken off and that they seem to give a slightly softer ride (still extra load rated). They are also much quieter which surprised me. Given the temperature and the fact they're brand new I was pretty gentle to start off with but although the feeling isn't quite as confidence inspiring there was no hint of oversteer as I built up the speed.
To test out their traction when applying the beans I sat in second with the revs sitting at 2.5k for a couple of seconds then floored it. No drama whatsoever, no traction control kicking in, no pull in any direction other than straight ahead. There was a split second of squirrely feel about the steering but it was blink and you miss it.
By now my confidence with these things was increasing so I was chucking it more and more enthusiastically into corners and using the accelerator with gusto. Much more spirited driving than I do on a day to day basis. Again absolutely no drama, although they don't 'feel' as planted as the michelins the car went exactly where I wanted with no understeer or any hint the back wanted to do anything untowards.
The only significant adverse behavior I noticed was that I felt braking wasn't as sharp as it had been with the michelins from high speed. I expect this to get better as the tyres bed in and the temperature drops.
Based on this first impression, especially considering the temperature it is today, I'm delighted that I bought these tyres and look forward to seeing what they can do when the real winter weather gets here.
Like Andrew has done I intend to update this as time goes on.