There are many factors that determine how fast data can be acquired, such as whether the data is in consecutive registers. In the ideal situation, if you read 100 consecutive registers from 16 different devices, I would estimate refresh rates with AdvancedHMI to be about 1 second.
If it is a question of whether AdvancedHMI can handle that much data, then the answer is an absolute yes.
When comparing AdvancedHMI to other SCADA packages such as WonderWare, I think in every case, you will find AdvancedHMI to be faster simply because it is a compiled application and not an interpreted one. However the trade off in many cases is typically the need to write more code to do tasks that may be canned in other packages. So when using AdvancedHMI as a SCADA, a decent knowledge of writing VB is important.