[ainarssems]

I think the experience vary a lot between drivers depending on driving style, car, tyre size and other factors. You can also have the same model tyre with tread patter and compound changing over time or for different regions producing different results. You can find that you like one model, couple of years by the same model or direct successor and it's totally changed.

I have Goodyear Eagle F1 on D2 in 255/45R19 and I am not impressed at all . Acceptable grip in warm dry weather but poor in either cold or wet. I do experience back stepping out as well even in dry and warm. I think they are the least grippy tyre I have had on S8 even including some cheap tyres which name I can't remember, they just came with 20" wheels I used for a while when my were off for refurbishing. My favorites are Michelin but I liked their older models better. Avon ZZ3 I found very poor in every aspect, no experience with ZZ5.

These days looks like most of the tyres are very fuel efficiency orientated compromising other characteristics. I see you mention UHP tyres, they do offer better grip but at increased wear. If on a normal tyre you can get 20-30k miles you will be very lucky to get 10k out of UHP and will also dry out and loose performance or start to crack over time more than regular tyre if you do little mileage and keep for years.

As for the cracks in tread, while they do look scary I don't think they compromise integrity of the tyre as the casing and tread are made of different rubber and while the tread is cracked the casing should still be fine as long as tread does not start to come off casing. Look at the airplane tyres, they retread casing several times with new tread and they still perfectly safe to use.