When they are good, I love Brett beers. But just as with IPAs, marzens, and saisons, I've had some great ones and I've had some awful ones. I don't think Brett/wild/mixed-ferm beers are categorically good. Some are amazing, some are terrible, and most are in between, just like any other beer.
I do enjoy Brett phenolics but only when they're mild; they can easily overwhelm, and this is my biggest complaint about the bad ones I've had: too much barnyard. This is, of course, highly subjective. I love the fruit esters they make, but of course production of phenolics and esters varies by strain.
Overall I can certainly appreciate what Brett strains bring to a beer. But all the home-brewed ones I've had (admittedly not many) have been ho-hum.
As it happens, I'll be trying my hand at Brett sour in a week or two. My plan is to use B. claussenii to primary ferment, and then add B. bruxellensis and L. delbrueckii in secondary for 6-12 months.