One of the reasons I was looking forward to 0.9.15/16 is the cleaner interface without the BookView/CodeView icons in the toolbar.
I get that there are BookView fans and I appreciate that KevinH and DiapDealer went out of their way to create PageEdit as an alternative for them.
For me, when I first started using Sigil, BookView was a source of frustration. When I realized there was Preview (and how I missed that in the beginning I don't know — must have closed that window without realizing what it was), I became a Sigil convert. Before that I was editing epubs using an HTML (non-WYSWIG) text editor and quite happy doing it that way. The combination of Code View + Preview + Sigil's epub tools have spoiled me to the point that the thought of editing epubs without Sigil makes me panic