Right now, performance tests bots take about 60 minutes to cycle. In order to add useful EWS bots, we need to reduce this time significantly to 10-20 minutes. Here's the list of tests sorted by the total time to run tests (on Apple's Mac port): https://docs.google.com/spreadsheet/ccc?key=0AqvOKf8yeFVCdGx4YzlUQzZJNUdodlcyWlpNRHduOVE
Let's make the target more explicit.