GenCheckinNotesUpdateWorkitem task is the most expensive and takes most of the build time. The problem is worst when you launched the build for the first time for a new build type. Why? What can be done about it?
Some statistics related to builds in Team Build (for simple HelloWorld.csproj project)
Disclamer: Please note that I was using low end build machines (my dev box with 512 MB ram). Moreover the data mentioned above is for a very small/dummy HelloWorld project with has negligible compile time. We had the alternative rolling build setup. When we builded all VSTF sources for the first time using Team Build it took 1 hr-17mins-28secs-57millisec to build. The build churned out 1449 changesets.
Client/BM on the same machine with configuration @ 2.79 GHz, 512 MB RAM
AT configuration @ 3 GHz, 1 GB RAM