I am on Resharper 4.x and VS2008.
R# seems to slow down the living crap out of VS2008. And of course, the memory usage can easily go to 500MB on a middle of the road Winforms solution with 7-8 solutions.
Now that Resharper 5.x is out, can anyone tell me whether either perf or memory issues have been improved for use with VS2008?