WOW, you really must drive like an old man.
I've managed 6000 miles on my (front) Assy 3's and i've got about 5mm left (or 2mm from the wear markers). Can't say they've lasted all that much longer.
I'm 95% of the time a motorway driver but when i do go for a razz, i'm not sympathetic to the machinery, it does gets spanked like it should.
Grip wise. The Assy 3's are not as good as good as the Conti 6's. In the wet i'd say they are as good as one another. But in the dry when doing the aforementioned spanking, i really really miss the Conti's feel.
Also i've just put on Assy 3's on the rear wheels and there's quite a noticeable wallow in the sidewalls compared to the rear Conti 6's.
I like the Assy 3's for wear rate-vs-price-vs-performance but outright performance wise, the Conti's trounce them.
Considering the price difference is £25 a corner you pays your price and takes your choice.
Next i'm having the wonder child that is MPS4s (which with my mileage should be about March).