These PPA's you have mentioned are maintained by
Webupd8 is quiet a trusted site. They provide proper well made packages stable packages. Many people (Even me!) use their PPA's. You should not have a problem with their packages.See their home page
Ubuntu-x-swat is also a great team. Here also many people use it (Me aslo, again!). You can safely use it but dont forget to read the instructions here
atareao : I have never used their PPA but searching around on the net gives a hint that they are a bit trusted and also recommended by some sites.
Generally most PPA's you find should be stable with no "evil" in them. Just to be sure keep a point in mind to add a PPA only if some sites recommend them. Also make sure to add only stable version of a PPA. Some PPA's provide development versions which might thrash your PC if they are buggy. So in the end the choice is yours.