I’ve got one (an exogrid) and love it, but to be clear, it fits into the 5″ XC category rather than anything more aggressive. As noted above, it’s got steepish angles, and tight tyre clearance, but it is plush over the bigger hits, and blindingly fast. I have mine set up with 140mm forks (Magura Thors) but wind them down for steep climbs, and 2.25″ tyres (Nobby Nics) and in that guise I’m happy riding 4′ drops and pretty steep tech stuff, but for more playful riding I prefer my 5 Spot.
One thing worth noting is the resale / second hand value is not great compared to Turner etc due to the lack of brand recognition here in the UK. No disrespect to Si, but I would say the same thing probably applies to Chumba. The other make that springs to mind with a very similar design is Nicolai, either the CC, or the rather tasty looking AC. As a complete bike, Lapierre also looks quite similar.