Which CEP product to start with?

Question

I want to learn more on how to build CEP based applications. So I looked around and found several products (overview found here: http://rulecore.com/CEPblog/?page_id=47).

But as there are quite a few at the moment, I don't know which is the best to start with. And overall I just would consider the one available for free. The rest is a bit to expensive for just private use ;)

Esper is for free, but without Esper studio it seems quite tedious to develop a cep app. Streambase offers a free trial, but I couldn't find out how long you can use this (if only for a month, no that helpful for longer research). Oracle CEP suite seems quite complete, but in the cep scene - as far as I can see - it is the least recognized compared to Esper or Streambase.

So do you have any hints on what is the best way to start with cep development? Is it worth to spent time on working through the oracle documenation or is it better to start with Esper or Streambase?

Cheers,

Andreas