In reply to WillBroad:
What for? These have been on the market for years as a twin rope, only recently certified as a half rope. I guess they occupy a similar niche to the Edelrid Apus 7.8, which I've used in the Alps and found great as a twin rope most of the time, switching to half rope technique for the odd zigzag pitch.
For permanent half rope use for UK trad I'd definitely want something beefier.
And you definitely need a belay device that's rated for skinny ropes, something like a Bugette of a MicroJul.