If you use your Bold mainly for calls, email, and BBM, OS 5.0 is still perfectly fine. But if you want a better browsing experience and don’t mind a learning curve, OS 6.0 breathes new life into the 9700.
For enthusiasts, a simple firmware change from RIM is too limiting. The Bold 9700 community has created — mixing radio stack from one version and Java modules ( .cod files) from another. For example, the famous BerryMe 6.0 Hybrid uses OS 6.0.0.723’s core but backports the browser from OS 6.0.0.800 (released for Bold 9780).
Unlike an app update, a firmware change rewrites the core operating environment. For the Bold 9700, this means upgrading from BlackBerry Device Software v5.0.0.x to v6.0.0.x—or even downgrading to a more stable carrier-specific build.