Well, sort of both actually.
Our American friends are an odd bunch and match the stuff with jam (which for some reason they call jelly), and even stuff it inside pretzels, but we Brits like to do things in style and anywhere that offers a burger that has cheese, bacon AND peanut butter on it has got to be worth a visit.
Alas, it doesn't work.
It is one of those things where every piece of the puzzle is perfect, but throw them together and it ends up just wrong; so much less than the sum of its parts. The peanut butter is just too cloying for the meats and cheese, but it is worth a stab. Maybe reducing the amount would work, but whilst the dead hippy sauce at Meat Liquor runs encouragingly into the meat's liquor, the peanut butter sits there, smothering everything.
So by all means try the combination, but don't judge the place on it alone, for the burgers are very good. The patties are seared at high temperature over a wood burning grill (the menu tells you what today's wood is: ours was cherry, although I'm not sure that I could have told the difference), so come our seared on the outside, the centre the perfect pink, with myoglobin dripping down your arm, as a good burger should.
Alas, I saw no sign of blonde, lithe, consummate gym-goers that the blogs promised, but we went mid Saturday afternoon and, other than the party that seemed to be roaring in the basement (they do an "experimental" burger making classes on Saturday afternoon), the place was deserted.
The cocktails were so-so, but the beers refreshing and the service attentive without being overbearing.
Up at the wrong end of Charlotte Street, far from the more restaurant laden end towards Oxford Street, and in a crowded space in the market, they need to stand out: peanut butter may not be the answer, but only because "does peanut butter go on a burger?" is the wrong question. So long as they keep experimenting, I will keep going.