Does the iOS 5 update still mess up your iPhone?

I got my iPhone in November last year and the iOS 5 update came out shortly after that I think. And I heard that whenever you downloaded it, it took away like all of your pictures and it had a lot of glitches like that. So I was too afraid to mess up my new iPhone. So currently my iPhone still has the iOS system before the iOS 5. But now I want to update it because my phone's been acting really weird lately and I think a new update would help it. Does anyone know if it will still mess up my phone? Or did Apple fix the issue?

I updated my iPhone 4 to it & never had a problem. So I don't see why not do the update.