[pbh101]

You put it well, and most people in this thread (including GP) seem in violent agreement.

In short: static methods are easy to test, methods using static methods (whether static or not) are more difficult to test.

My takeaway: the bar for moving functionality into non-static methods (which will still be decently easy to test) is quite low. If you call a static method, be prepared to own all its functionality when testing the calling method. Taken to logical conclusion, public static methods should be quite small.