Far and away my favorite hone, Belgian coticules are communicative, entirely repellent of metal, given to wear rather level (unlike waterstones), fast enough for most razor-related work, and not terribly difficult to learn. They do require practice, and they rarely yield near-instant excellent results (as does a Norton 4000/8000 stone). They're inappropriate for repairing neglected razors. Though capable, they're much slower at bevel-setting than 1000-2000 grit waterstones/diamond hones. The bottom line, though: for refining/finishing/maintaining properly-beveled razors, they're awesome....what other single hone takes you from rough condition to shaving sharp in 30 minutes? There's good reason folks are cuckoo for Cocoa Puffs for these rocks.
Coticules transcend hype or flavor-of-the-month inertia. I believe choosing to "live the straight razor life" is much about placing equal value on processes themselves versus merely results. The coticule's visceral, dynamic, and rewarding process, according to myself and many others, can't be duplicated by manmade hones. When the (certain) day arrives that there's not enough coticule supply for us to distribute, I'll still believe (to obvious detriment of hones we WILL sell) anyone coming to truly understand their coticule wouldn't choose something else by preference. Whilst hopeful that's many years away, I'm realistic; it isn't.