Although I work for Symbian for about 2.5 years now and truly think it is a great operating system there are some things I don't like. I don't like that you cannot write for Symbian, instead you have to write for S60, UIQ, MOAP-S and etc. I think for development it is a nightmare. I don't like that there are no SDKs for MacOSX and Linux. I don't like that the documentation is not very readable and nothing compared to Java SDK.