I’m sorta fond of Knipex in general but I’ve never used their locking pliers and they look almost “run of the mill” but looks can be deceiving so I just don’t know, If I were looking for high end lockers’ I would take @ToolGuyd’s opinion to heart.
I don’t know about any Knipex-Facom connection - but many of the Facom locking pliers have no Knipex equivalent that I can see - and they are said to be made in France.
I hadn’t realised that Knipex made grips.
The Facom designs are nice. Although Facom is no longer independent, I’ve always liked their stuff and I think their quality is still some of the best on the market unlike many famous brands that have deteriorated badly.
From memory, I think that German Stahlwille also make what us Brits call “mole grips” aka Vise-Grips. I have a handful of Stahlwille spanners from 20 years ago and rate them the best I’ve ever seen. Superb steel, good finish, very slim. Their vise grips seemed very generic but I would still trust the brand.
Harry J Epstein has started carrying BollmannGrip pliers which are also made in Germany. They have a few models that Grip-On doesn’t make. They are fairly nice, but I still prefer Grip-On. I have no experience with Knipex.
What do plan to use them for? I’ve found that I almost always grab the knipex pliers wrench for almost everything I used to use other pliers for. Wiha makes a pliers wrench as well but only in one size as of yet. The pliers wrench has parallel smooth jaws with parallel clamping motion and extremely high clamping force.