I've said this before, possibly worth repeating on this thread. Our car is a 159 SW Ti, 2.4, remapped and DPF deleted. So 19" wheels, plenty of poke and both the missus and I drive "enthusiastically".
So, we got the car second hand in June 2012 with a set of brand new Acceleras. They were fine. Having read a lot of threads on here, I was wary to start with, but I really couldn't fault them. Dry or wet, they performed well. I was cornering with at least as much confidence as my 156 V6 which is running PS3s. I had an epic "standing water" moment at hight speed in October and the car didn't twitch. So far so good.
It changed as the temperature dropped. I remember at about the time the clocks changed I was driving home, cursing the weak headlights (now HID-ded), and wondering what had happened to the grip - it was about 3C. The car was pretty much all over the place. The next day it was warmer and the grip was back.
I was planning to get winter tyres anyway, so a set of Falken Eurowinters are now on. Grip is restored.
So I think Acceleras are fine as a Summer/Winter combo. In the summer they are no better or worse than any other tyre, because grip on warm tarmac is pretty easy to generate. So you can cane it round roundabouts safe in the knowledge that you only have £200 of rubber on the front. When winter comes, you can use all the money you've saved on a spare set of alloys and winter tyres, which are likely to be better than any premium "all season" tyre for cold conditions.