I haven't found anywhere that someone asked this - so my apologies if asked and answered...
I'm on a development team that uses Flex Builder 3 - but I am running Flash Builder 4 (x64).
When I generate the service proxies for our WSDL - the Flash Builder 4 output appears to be substantially different than the output from Flex Builder 3.
Is there a compatibility option that I can set such that FB4 will generate the wsdl service proxies output that matches the FB3 output?
There is no such option. The old WSDL wizards are replaced by Data Centric Development (DCD) feature which provides a better and simpler way of using services.
More about using the DCD feature here - http://sujitreddyg.wordpress.com/flash-builder-4/#webservice