I loved my 3.0's to death, literally.
I ran in them until the sole wore all the way through on the toe end.
My best summer of mileage ever was all done in 3.0's
I've gone through 4 pairs.
I found them to be great for everything off the track: regular runs, long runs, tempos, hills, mile reps, road, trails, whatever. I even did some road races in them. They're light!