I took the plunge last week and purchased the Oro. I already have a Eureka (Zenith 65e), but wanted something smaller and less wasteful. I liked the look of the Niche, but due to a combination of availability and my wife preferring the aesthetic of the Oro for some reason (this is often a major deciding factor where my coffee kit is concerned and means I no longer have to house the grinder in another room!), I went for the Oro.
It’s early days, but I’m really enjoying it so far. The bellows seem to make little to no difference , but other than the very first few shots I used it for, the grind retention is within the tolerance of my expectations (typically 0.1 - 0.2g) and often zero. It’s considerably quieter and faster than the Zenith and seems much less clumpy (in fact, I’ve not noticed any noticeable clumping). Grind quality is lovely and fluffy.
From my perspective, I’ll probably always hanker over a Niche (and I’m also not sure how I’m going to deal with the odd occasion when I want to grind a whole bag of coffee if I get rid of the Zenith, although that wouldn’t be any different with the Niche, I suppose), but I’m satisfied enough with the Oro for the time being. I’m used to the rediculously fiddly changes if I fancy anything other than Espresso, so that wasn’t a deal breaker. Overall, any compromise is acceptable to me and it appears a solid bit of kit.