Having owned the Fujifilm X-T1 for over six months now and used it on a regular basis, I find it difficult to point out any serious design flaws. The chassis is solid, the various buttons and dials are easy to access and turn, and the front and rear grips for your hand and thumb are both substantial and comfortable. We were even lucky enough not to experience the dreaded light leak issue of the first batch of X-T1s, so all in all, we are dealing with a near-perfect design.
However there are a couple of accessories that can make the user experience with the X-T1 (or any camera for that matter) even more enjoyable, namely thumb rests and soft buttons. And to our delight, we recently received one of each to test on our beloved Fuji.