Looks like Gorilla Buck bought out the previously defunct Vbuck:

Press Release

VBuck's website has reflected this for a few weeks. I noticed this when I read a thread here stating RIP VBuck so I went to their website and saw they were still in business but under new ownership.

I was originally interested in VBuck for my future home but I think I'm going to go with PreBuck instead.

B2L- How did the PreBuck work out? I like the concept but can't find much from actual users...

I have been using Pre-Buck exclusively since it was in development. It helps that it is manufactured nearby! I usually get them pre-assembled, but have used the knockdown product quite a bit too. I have little negative to say about it. 1) Use gloves when handling it because the metal flange can be a bit sharp. 2) The metal flange can get pretty beat up, and if it isn't tapped back "straight" before drywall, will affect the thickness of the extension jambs during trim stage. We tap them out somewhat in order to set the frames when we are a course or two above the sill height, then tap the flanges back in before pouring and again before drywall. I would MUCH prefer a plastic flange like V-Buck had. Positives (in my opinion): 1) Very strong-- needs less bracing than even dimensional lumber, and can fasten even concrete filled fire-rated doors to it with a lot of confidence 2) Will not warp, cup, split, etc. 3) Airtight due to the twin dovetail grooves 4) Well bonded to the concrete, again due to the twin dovetail grooves 5) Less labor to assemble and install--doesn't require a bunch of plywood/strapping 6) Builders don't freak out about not having anything solid to connect to.

Thanks Jake!