Upgrading Advantage & Disadvantage

Dear Friends!

i want to know what is the advantage and Disadvantage for upgrading the new version for NAV. Currently

I am using NAV 5.0, i am happy on it. shall i change into new version?

That completely depends on your business and what it needs. I would at least consider upgrading, as a new version will be out fairly soon, and at that point 5.0 will no longer be a supported version. Ask your partner to demo some of the new features of NAV 2009 R2. You have the role tailored client, NAV over the internet, web services for integration, just to name a few.