Some metrics that we captured on my project: (I think the numbers speak for themselves)
| Operation | VS 2005 | VS 2008 | % Improvement |
| Start the IDE | 00:30 | 00:09 | 70% |
| Load solution | 03:45 | 00:45 | 80% |
| Get Latest (no changes) | 00:13 | 00:05 | 62% |
| Rebuild solution | 02:21 | 01:58 | 16% |
| Run all tests | 05:29 | 03:44 | 32% |
| Start the application | 00:19 | 00:18 | 5% |
FYI our solution has 33 projects in it (including a database project, a web application project, numerous DLLs, an EXE and a WiX installer) and there are almost 1,600 unit and integration tests.