Well Craig,
That's what I mentioned Overall, Latency, Bandwidth, Performance,Speed of Upload/Download in to QC. Cannot be Simillar in all the environments.
Will vary if you consider / Compare two versions (Previous VS Immediate).
A simple Concept of Knowledge, You cannot fit all your books in your Old School bag when your Standard moves on. you need a new school bag, which covers & fits your requirement. Just like New version of application needs some more Rather than the old and Performance will obviously Observed (LIL DOWN)...Whether in Latency, Bandwidth...or what ever the terminolgy is..!!
By the way Heart of the question is any one Documented these..??