RTMP better than Comet?

I'm coding a Flex application and I have to choose a good backend configuration for my needs. ( real time data push )

I wanted to know if RTMP is better than Comet http long polling ?

1. In fact, I want to compare GraniteDS and Red5... Both are capable of data pushing but red5 uses RMTP, so in terms of performences, clustering, large amount of clients, which one is better ? GraniteDS ( with Gravity and maybe ActiveMQ ) or Red5 with his RTMP protocol ?

2. Another question is : in Red5, can we specify multiple end point ? ( to have a large scaling ). I know that we can scale a huge project with ActiveMQ and GraniteDS but I don't know about Red5...

3. As far as i under开发者_Python百科stand, we can use GraniteDS backend to other clients than Flex ( like HTML/AJAX ) because it's Comet like... and RTMP concerns only Flex/flash client. Am I right ?

Thank you for your support !

This is somewhat subjective but here is a link that may help:

http://qnatech.wordpress.com/2009/07/28/blazeds-vs-graniteds-vs-lcds-vs-red5-how-do-they-compare/

Have you considered to use Websockets?