> Im currently using Firebird 1.53 and is stable,fast and reliable, I
> need to know why should I use Firebird 2.0? what's new? is more
> stable? faster?

If it aint broke, don't fix it.

> What are he reasons someone like me should switch?

There are significant improvements, (fixes and enhancements) as
detailed in the release notes ranging from optimisation improvements
through to incremental backups through to better unicode support. Will
it benefit you? Maybe, maybe not.

Firebird 2 is not released though. Release Candidate builds are
available for you to test, but you should understand that there may be
some bugs that cause you to lose some data, so I wouldn't use it in
production yet unless you are desperate for a given feature.

Adam