ok, I used a bunch of bottles from Unibroue (Fin du Monde 750ml's) to bottle an american wheat yesterday. Observation is mostly that the hassle involved in getting the damn (plastic) corks in there and then clamping them is a major pain in the arse. The clamping in particular -- I suspect there may be a machine to do that properly, as doing it by hand is a recipe for pain. Moreover the cork + clamp combo is relatively very expensive compared to crown caps -- depending on your sources it looks like about 10x more expensive: I pay about five bucks for 100 crowns, and I paid 15 bucks for 30 corks/clamps.
Mostly I'd recommend that if people are going to use larger beer bottles, that they stick with those that can be capped with crowns.
I'll probably revisit this with proper champagne/sparkling wine corks when I get a corker, but the clamp + cost issue still stands.