I spent ages researching tyres as well. ended up with 4x 452's. Seem to be alot of people with heavier cars (ie is200) taking them off before end off life. The other thing is its equally important to make sure the tyre has a high rating or you could end up blowing out a side wall.
Anyway, done 300 miles on my 452's, you wont be disapointed. I've 'tested' them where safe to do so in wet, dry and loose, better than the bridgestones that were on it before. Had an oh SH** moment on a wet gravely country lane. Had to make a sharpe right turn and thought it was time to say hello to the bush but no, gripped and turned.
They are supposedly better on MPG but if they are its not noticable. Also, theya re a marked improvment on road noise from the bridgestones.
I shall be buying again :)
Chris