Hi Angelo, thanks for your insights. Finally I ended up doing a similar thing. Since I get my data from PHP Services, I now just send back a print request, which generates the PDF and sends back a link to it, and the Flex Client can navigate to it. I find that this is probably the best solution if you need complex pdfs to be generated, as AlivePDF and FlexReport etc. still have some limitations and I also dont know about their performance.
Thanks for the insights, Martin