I have read about the negative points of the update. But should I do it anyway? If I don't like it can I go back to 1.5? I also didn't see if it fixed the youtube problem. Pleas let me know I'm still on the fence about updaing from 1.5

Is it worth the trouble?

The update did fix the YouTube prob. And update includes some gr8 features such as voice search a better multi search ( when u press the search buttonon ur phone it will search ur entire phone message, apps ... . And the web of course ) but the those slow down ur phone , - about downgrading ur phone never did it but it says that it is possible