I initially contemplated keeping both, as the rwak's bass response with the ie800's is thunderous. The tera's bass is certainly more rolled off in comparison. Ideally I would like to keep both but my listening time is quite limited these days. I think the tera has a more natural and resolved midrange. For me, the tera is more musically involving. I am not experienced enough to be able to articulate why, I only know that during that last few days, I could grab either one with ease and I kept coming back to the tera. The rwak, otoh does have more treble extension. It is also a beautiful device, and I am always worried I am going to break/scratch it (which I haven't). The tera is more rugged and feels almost indestructible. I know some much prefer the interface of the ak/rwak, which I certainly understand. But I actually prefer the minimalist interface of the tera. In the end the combo of musicality/minimalist interface won me over.
I agree, I was also worried about scratching up the RWA AK100 lol. Those leather cases look like a good solution though.