They're made in south london, I found them in east london.
Plantain works really well as a crisp, the crunch is deep and the flavour isn't that sweet. If these had some salt on (apparently they do but I can't taste it!) or a different flavouring, I think they would work really well as an alternative crisp. I can imagine a posher crisp brand doing these really well.
But for the moment, they are lacking in flavour - I see these as a base from which an amazing crisp can be made.