Softwares are available for both Java and Symbians. But Java is just sooo limited. Java generally can't access resources outside the application. That means nothing like mp3 players, videoplayers, emulators with later addable Roms, etc. Mostly, the apps in Java range from Calculators, to dictionaries, to E-Book viewers (again you'll always have to bundle the e-book text files to the setup before sending it to the phone as Java can't access resource outside the application), to a Nes Emulator which play without sound and have the same case with roms as Ebook apps, notes/password keepers etc etc. That basically is the type of apps you'd be getting on Java. Go through 'Getjar.com' for bigger list of that.
Good thing - its simple, bugs free, no virus's etc.
Apps on Symbian are unimaginable. Its like a windows initself, so the first priority will be to get an Antivirus and even a firewall (like Symantic's) hence all phones with S60 are automatically classified as a 'Smartphones'.
Lets just leave it there.
Good Thing - Symbian enhances your phone even if the Developer hasn't implemented those features. The N70 was never quoted to play Mpg's, Avi's, Ogg's, Rm's and so on...yet just with the apps part of Symbian you can easily install video and audio players that would play those codecs! Now imagine if that is only the start and basics of Symbian.
Coming to games - I guess no one has the edge here. 3D Java is just as good as 3D Symbian. Besides, the gaming market mainly focuses on Java games. Symbian games are very rare, because even Symbian 60's can easily do Java. So both will do equal in gaming.
Conclusion - If you're the kind of person that would want heavy customizations, advanced 'Windows Like' applications, then get Symbian. If you want Hassle Free phoning, very simple OS then get Java enabled non symbians.
). But yes I have a 6630 and an N70 and its easier on the 6630, but believe me once you get used to a cell then u won't notice the keypad as an irritant. U just need ta get used ta it..