VS2010. Mainly the fact that the user interface is painfully slow[1] (either that or I'm unreasonably fast which is rediculous as Vim can keep up with me) and it just dies about 5 times a day on a good day. It might be the solution size though - it's got about 0.5 million lines of C# in it. Still it should work.
[1] On a quad core Xeon with 12Gb RAM, SAS disks and ATI FirePro card.
That size of codebase is definitely an issue :) Last time I had 500k of C#+C++ (5 years ago roughly), I split the solution into around 20 solutions, and used binary dependencies (with CruiseControl.Net on top of that [1]).
I remember reading similar advices in other places as well (and for other languages/platforms, too).
That looks painful. I'd rather like to move it to an SOA and split it into logical feature partitions and use service composition and windows workflow to integrate it all. Typically, I don't think anyone wants to pay for that though.
