As did JD from Adobe:
My take. Use the right technology for the job. If you need UDP you
can't use Flash. If you need to rely on a runtime that everyone has,
Java is not for you --- yet (Consumer JRE blah blah).
It's unfortunate that your users don't have updated versions of Flash.
I used to hear this kind of thing pretty often but now it doesn't seem
to come up much. But it certainly depends on the audience ie. you can't
expect people with green screens to have Flash Player 9.
We do publish version penetration stats which is a general analysis
(corporate and home users):
However I always recommend that people setup a version tracking sniffer
for their audience before they decide on Flash (or any new RIA
technology for that matter).
I'd encourage you to file bugs on any inconsistencies you find:
Please let me know the bug numbers so that I can follow up with