I have done a few 100% Brett beers and haven't found one I don't like yet.
I've done WL Brett C with a Brown Ale base - really brought out the roast and fruit flavors. For the first month there was zero funk, now at 6 months it still has the roast but much more funk and just barely tart. I am really getting hooked on the roast - sour flavor combo.
I also did a Drie / Avery 15 Brett Strains in a Special Bitter wort and it was a tropical fruit bomb for the first month, which was nice with the floral hops. At 6 months it has some decent sourness and the hops/bitterness have fallen-off, but still has a great caramel malt and big funk aroma.
http://jeffreycrane.blogspot.com/2011/01/dreg-series-avery-15-or-drie-brett.html
Since I liked the Bitter so much with Avery 15 dregs I tried some in an Old Ale wort. And like others have spoke about above, the beer started out with some great fruit notes that went very well with the dark fruit from the treacle. But now the beer's nose is very funky with some of that fruit flavor still there.
http://jeffreycrane.blogspot.com/2011/02/dreg-series-old-ale-with-avery-15-brett.html
I have yet to find a wort I don't like with Brett fermentation. In my opinion, it just takes a bit more thought about the evolution of the beer. With my experience from WL Brett C produced a very clean beer with some citrus component and then the beer turned musty and funky in a good way. For the Avery 15 Brett strains they started out over the top fruity, like a fruit cocktail and over time have developed some sourness and a bit of funk.
http://jeffreycrane.blogspot.com/2010/12/dreg-series-brett-c-brown-ale.html
There is a lot of experimentation still to do. Also some things that were not mentioned, but make a big difference in the flavor profiles are aeration (mine were not aerated after pitching and i had no sourness for the first couple months), pitching rates (my pitching rates were low about half normal sacc rates), pH of wort before pitching (I did not pre-sour my wort) and temperature (mine were done in the low 70s). Chad Y in his Brett Project dissertation covers some of this. If anyone has done any side by side experiments that might also help the OP know what he might get from a 100% Brett fermentation.
Good luck and let us know your results.