well, rooting lets you use apps like titanium backup, to backup apps+data. make a nandroid backup. install apps that needs root, install xposed modules, which neglates the point of roms... its very good. even without custom roms, if you are still new in this. please read a lot first before doing anythin above.
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Exactly. Also you can use Xposed framework, which can give you most of the benefits you would previously get with a custom rom.
I have Wanam's Xposed and it let's you customize almost anything.
The only mod I have done to the ROM is to remove the quick connect and S finder shortcuts. The rest is all Xposed
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