[Q] Restoring apps and data
I'm new to rooting and custom roms, so far I've rooted my s3 (i9305) and added a custom recovery. I'm currently looking for a custom rom to update the stock version I'm currently running (4.1.2). I have titanium backup installed and everything is backed up, however many of the posts I've read suggest not to restore apps + data from titanium backup. Can anyone explain why, is it just titanium backup that causes problems? What about using other backup apps like helium? Can I restore just the apps using titanium backup, or should I download from the play store instead?
For me the most important stuff is contacts and calendars (which are in my google account), so that's easy as I just re-add my account. My call logs and SMS are backup to my google account using SMS backup, so I assume it's ok to restore this data as well, I'd also like to be able to restore my firefox data.
Any advice would be appreciated to a noob, I know how to do it, just want to know what the potential risks are of restoring apps and data.