Well yes, but all the warnings and cautions in that link apply equally to PPAs - the security implications are pretty similar. A novice using PPAs will be in the same boat, though admittedly PPAs are a little easier to use.
Oh I was being a little tangential and pointing out that changing packages on Stable to an extent defeats the purpose of it. I just hope they don't start releasing PPAs that'll help people achieve worst-of-both-worlds systems that combine the outdatedness of Stable and the bugginess of Experimental.
