Pete,
You've got to think carefully what you'll get away with for a keyring knife in the UK. I always reckon that the nicer the knife the more likely you are to have it confiscated by plod! I have two fireflys, neither has a 50/50 blade, mine both have a plain edge. They are easily sharpened, discreet and cheap enough that if you lose them, who cares. I was given a present of some coast micro-pliers, an alledged micro-tool, what a chunk of s**t. There wasn't enough quality to measure with a scanning electron microscope (this isn't the micro toolbox).