Generally I've been very impressed with WI over the last couple of weeks of using it - a much more pleasant experience than NB!
There are various niggles that I'm sure will be fixed, but I've got a showstopper. Sometimes, WI seems to decide that it dislikes one particular file for a while. If I have open it in the IDE, or switch to it from another tab, the whole app freezes - text cursor stops flashing, menus are unresponsive, can't quit. If I force quit, relaunch, close the file and reopen it, the same happens again. I don't think it's to do with the particular file - it's just PHP and it has been edited that file successfully before. It seems to be intermittent - sometimes it works without a problem, other times it just hangs up. Sometimes it seems to get over it and all starts working again, but then start doing the same with some other file. The same files work fine in BBEdit and NB.
I know NB can grab memory dumps or detailed profile logs of itself using it's own Java debugger - is there some way I can do that with WI?
FWIW I'm running 701 on 10.6.2 on a Mac Pro using 32-bit Java 6.