I have a flash project that polls a php server every 10 seconds to check for commands. I have 1200 machines running this on a local network.
When we have network slowdowns, polling sometimes fails and the project hangs. Is Blaze/LiveCycle well behaved on thin networks? Is it more robust than polling under these conditions?
It's not so much the polling (or pushing) part that would make a BlazeDS better/faster. What would make it better (probably) is if you use BlazeDS and only send data when necessary, and only what is necessary -- thus limiting the overall traffic. It sounds like polling hangs because at some point in time you end up sending a lot of data and it takes Flex a while to injest that data.
I've run simulations with 8000 entities pushing state (an object with ~20 string fields and 2-3 large lists of strings) to Flex via BlazeDS and performance was OK.