Is the Galaxy S II stable? I am thinking about getting a Galaxy S2. It seems like a great phone, but I have some concerns about the system stability.

I hear from Android users that Samsung's original ROM is very slow and heavy (and doesn't handle right-to-left languages very well - I speak Hebrew), and that other ROMs have their own problems and the releases are not so reliable. 

Is any of this true?
As an Android user for about 2 years (and an iPhone user for 2 years before that), I feel that Android is very stable.

BUT you have to remember, that with the ability to load widgets, and background applications - you can certainly bog down your phone and decrease its performance.

In Apple's walled garden this isn't a problem, but you also don't have the freedom and choice.

As a modern computer user, I want the choice to slow down my phone if I want :)