Is Informix Reliable?

I am currently evaluating Informix -vs- Oracle, and would appreciate your input. I have read on a few threads that people have had to unload and re-install the database to fix corrupted system tables, indexes, etc.. How often does this happen? Also, how reliable is Informix in client/server code, as compared to running code on the same machine as the server? Are hung sessions rare or frequent? I need sessions to be able to stay up between middleware servers and the Informix server for months at a time. Thanks