I would like to try Adobes products, because:

• It's the easiest to use RIA platform for developer.
• The browser runtime(Flash Player) works much better than competition. In fact for years without big problems. In contrast yesterday the Java6u13-VM didn't start while entering a site with an applet, although the VM is stable enough for BIG, BIG servers.
• Mature runtimes are available for all platforms. (Windows, Mac, Solaris, Linux, 64bitLinux!). Valid for Java, too. But not for MS GreyShadow.

However there are some major problems for me:

• There is no Flex Builder for Linux. End of story :)
• It's a proprietary plattform. No standards that I'm aware of and closed runtime software. That hinders innovation. It's a pain for developers in the long run to work with a black box. Think about the Java VM. Nowadays we like to run Scala, Ruby, Python, and Clojure on it. It can run directly on a virtualization hypervisor (JRockit). It runs in little different flavours on small mobile devices (Android). If there is a problem, we can check the code.
• Who needs an open source SDK if the runtime is closed?

I will have a look when
Adobe releases a Flex Builder for Linux
and?/or?
Adobe opens the sources/standardizes the VM.


Update: Someone else has the same opinion: Mike Slinn: Flash Builder, Linux and Winning the RIA War