Because straight/draft Lambic isn't discussed enough, and we can always use more pictures, here's some I have from TdG...
Girardin (3yo, iirc), at De Groene Poort in Gooik. It did have a small thin head when it was first brought to us, likely from a sparkler. (The similarities to British serving style were intriguing to me. All of these were served at near room temperature as well.) This was at some perfect nexus of complex and easy drinking. You could barely call it tart, but the taste was deep and full. Flavors of tea, herbs, subtle funk, must, low acidity.
Cantillon, I believe the same 13 month we had elsewhere. No idea how/why it's lightly carbonated. The head is due to a sparkler again. Taste is Lemon flesh and pith, aged hop, tart but still with a bit of wortiness. Very excellent and highly drinkable.
Here's the full lineup from DGD. I should have taken notes, but was too busy enjoying/blending etc. I do recall that the Girardin was similar to what I've said above, and the Boon was very very Boon. Just everything in near perfect balance, with that great lemony funk the Gueuze often has.
This doesn't really count since it's at the blendery, but this is De Cam 3yo unblended Lambic. This cask was open because they were blending Gueuze at the time. Absolutely incredible stuff. The essence of De Cam in a glass. I don't have tasting notes, but I remembering it being bright but balanced, having a very long complex taste. Kind of like Boon gone a bit wild. Excellent.
Finally one of the more beguiling Lambics of the trip. This was Girardin, very young (I want to say 6 months). It was like some kind of amber Wit, with a faint hit of aged hop and barely discernible acid on the back end. It was stunningly full bodied, but very refreshing. Could put down gallons of this.
So yeah, TL;DR: If you are ever in the Senne Valley, seek out draft Lambic!