What percentage of users have the Flex 4 framework SWZ cached in their Flash Player?

Question

I am trying to make the case that using Flex 4 with RSLs is more sensible than developing pure AS3 applications with no Flex or Spark at all. In the former case, file sizes are comparable to the latter, save for about 2 MB worth of RSLs. However, it seems logical that the vast majority of users will already have these assets cached.
So I have three questions:
Are there any statistics on what percentage of users have these SWZ files cached already, and therefore won't need to download them at all?
Is there any way of determining, in my client-side code, when a user loads the file from the FP cache, as opposed to downloading it from my server?
Is there a performance difference, in terms of total load time, for loading a cached SWZ file, as opposed to simply embedding the framework and not using RSLs at all? Disregard bandwidth and downloading times.
I have heard that Adobe hasn't released any official statistics, but I'm wondering if anyone has done their own testing with server logging.

Answer 1

I don't know of any statistics.  It might also depend on the demographics of
your users.
There is no way to determine for sure where the SWZ came from, but you could
probably guess by looking at getTimer() somewhere in your code.
Ignoring bandwidth and download, the SWZ has very little overhead, but it is
there.