I never posted in this section, but this discussion provoked me to respond.
From mid to late nineties, I owned a flooring company, specializing in all types of flooring (carpet, hardwood, vinyl, tile). That gives me some credentials to speak about the OP's question about Berber.
And since I am on this forum, that also means that I am interested in vacuum cleaners more than the "normal" guy. And also, I am soon to be 60 years old, so I am not out to impress and/or prove anything. I also live with four large dogs (two GSDs, and two Alaskan Malamutes, basically two couples).
And here it goes,.....in my experience with Berber carpet, it's just a matter of time before the dog pulls ONE loop out of the backing (either by running, playing with a chew toy, or else). IF one runs ANY kind of powered nozzle (with rotating brush), the brush WILL grab the loose loop, and "pull the line" across the carpet. I've personally witnessed, AND experienced this in my own home, and MANY client's homes over the years.
Another consideration is pet "accidents". My company replaced thousands of yards of Berber that was either stained and not cleaned very well, or cleaned with wet extractors (and they all have powered brushes), and damaged. Wet extractors work on pet "accidents" only if the agitation is used (along with water and detergent), and the agitation is ......powered brush or brushes!
IMO,....Berber and pets DO NOT mix, and if Berber is a MUST, suction ONLY vacuum cleaners have to be used.
Of course,...we all have our own opinions, but this is something I experienced on numerous occasions, and once the "line is pulled", the ONLY remedy is to replace the carpet in the whole room. Since some time might pass from the initial installation, and the needed replacement, the matching "dye lot" of the original carpet might not be available. In one instance (because of the layout of the home, and the location of the damage), we had to replace the carpet in the whole house to match! Needless to say, the owner decided NOT TO go with the Berber again. In MY mind, the choice is clear,....either Berber, or pets. I love my pets,.....so no more Berber for me,....ever.
Good luck.