As the name suggests, the Berlin HC is made of hard compound rubber as it’s intended for rear wheel use only. This needs stressing as, although it offers greater wear resistance, the harder compound gives much reduced grip so it’s no use at the front.
Halo rates a Berlin up front and Berlin HC out back as its ultimate combination — we've been riding this combo for a couple of months without a single flat. However one of our courier mates has gone through a basic pair in similar time (too much skidding!).
PROS flat resistant, ideal for fixies CONS not for everyone