I have been using ReSharper since around the 2.0 timeframe.  I am completely dependent on it for my daily work, but I am very frustrated that they still haven't come out the 4.0 version.  I've been running the nightly builds for a few months, but that is hit-or-miss.  I really want a stable version that has full support for the newest language features.  I flirted with the idea of going with CodeRush, but my fingers already are fluent in ReSharper and I've already invested in ReSharper.  I can get 4.0 for an upgrade price vs. $250 for CodeRush.  Do the math.