I bought the Hugo 2 because I thought it sounded better than the Mojo when I initially compared them, and then for months thereafter. But when I introduced controls into my comparison and used a switchbox so that I could switch quickly between them, all of the sound differences I had previously perceived disappeared. The Mojo wasn't warmer, the Hugo 2 didn't have more clarity, etc. It was a shocking result, but it is what it is. I can't rule out the possibility that there could be subtle sound differences between them which aren't apparent from my comparisons, but I think any such differences are a lot smaller than the differences between headphones. I'll send you a PM linking a thread where I discuss this in more detail.
In general, it's very easy for us to misperceive differences between gear, especially when we know what gear we're listening to (that creates "expectation bias"), don't match music segments and volumes, and allow several seconds or more of time gap when comparing gear (research shows that expectation bias only needs a few seconds to kick in). And we don't generally know or believe that we're misperceiving, because our processing of perception largely occurs at a subconscious level which is hidden from us. A good general read on this topic is the book Subliminal by Leonard Mlodinow.
