I spent an hour or so working with a couple folks from Red Gate this morning to run through the latest build of their ANTS Profiler v4.0.
ANTS 4 is still in EAP (download latest bits here), but I was awfully impressed with the state it's in. I downloaded the bits, installed it, ran a quick session on a monster WinForms app I've worked on in the past, and quickly got down to the guts of some possible performance issues. The UI's nicely done, and I was very, very impressed with the app's responsiveness. I'd all but given up on ANTS 3 and dotTrace because of nearly unusable performance while trying to profile a couple apps.
ANTS 4 still has a way to go. There are some bugs running around, and some UI tweaks need to take place, but overall I liked what I saw with this version. You ought to go have a look at it if you're interested in an easy to use profiler.
<disclaimer>I get some software from Red Gate for free because of my MVP status. That doesn't stop me from criticizing if needed.</disclaimer>