You can do a lot with a helmet for £100 and Cratoni's Achillon is a minimalist, sliced and deeply sculpted head topper. The amount and depth of apertures certainly does wonderful things for the ventilation too, dragging air across your head and out the back in exactly the way we're looking for in a top price helmet.
The vestigal, non-adjustable duck peak doesn't add much shelter or supercharged airflow, though. At least that meant we didn't miss it too much when it started to fall off (first just one side, then both) with irritating frequency, until we just left it off entirely. Apart from that, all the furniture is decent, with easy to adjust straps and a fat skull pad to cushion the 'dial a grip' fit cradle. Slivers of super thin pad also make sweat accumulation minimal, although you'll have to peel them off carefully when washing not to disturb the tiny Velcro pads they rely on. Two shell sizes ensure a decent close fit, although despite hardshell coverage being more patchy than the £80 Tremor, weight is average rather than low.