I had a pair of Nimbus 12s and ran with them for about 1.5 years at 10-14 miles a week and they were the best pair I've ever worn.  I upgraded to the Nimbus 13s and they feel just as supportive and comfortable.  The arch support in the Nimbus shoes is what really sold me compared to cheaper running shoes.

Like most running shoes, they take a run or two to break in.  I feel no ache in my joints after my 7 mile run with them from last night.

Make sure you check your running motion (neutral, over or under pronation) before you buy anything though because these shoes are for neutral and slightly over pronation runners.  Asics' website will tell you what shoes of theirs are good for each type.

UPDATE:

I've worn them on three runs of 4+ miles and the cushioning is still what I expected, running on pavement left no pain in my legs.  Asics must have slightly changed the sole of the shoe where your baby toe sits because I've gotten some uncomfortable rubbing about 3.5 miles in to my runs.  It probably is due to me not breaking the shoes in yet and I have been wearing new running socks that might be shifting since they had that slippery coating on them still.  I think Asics put more of a depression in the sole for the baby toe to sit.  I still like the shoes though, will monitor if this goes away with more breaking in.

UPDATE #2 (1/12/12):

After owning these shoes for more than 6 months now, I like them better than I initially did.  The toebox is smaller than on previous Asics shoes I've owned so finding a sweet spot in the lacing was tough.  I had to loosen up the lower laces and keep the upper ones tighter to prevent shoe slippage.  My right foot would go numb after 3.5-4 miles before I could find this sweet spot.  Now I have no issues with that.  The cushioning is holding up well as I have zero knee fatigue or pain from my 5-7 mile runs.