A significant issue regarding viz calculation times has been discovered in QSDA 2.1. QSDA uses a technique to bypass cache to ensure that all timings include a complete calculation. This cache bypass technique is not working in 2.1. The first time an app is loaded, the timing will be correct as there is no cache entries. On subsequent analysis, cache will be used and the timings will be too low.
This issue is being investigated and a fix will be released as soon as possible.
-Rob