Actually, "all quads" makes the modeling process easier: you get to take advantage of the loop tools (loop cut, edge slide, etc). Clean topology makes it easy to add or remove detail as you need it. Triangles do not make for clean topology as they break the flow of edge and face loops. Once you've got your model "done" (animation too?), then you convert to triangles (and if necessary, rotate them).
I don't know where you've been hanging out for your modeling info, but everything I've seen has been almost the opposite:
do post wires. If it's to be a subdiv model, post smooth shots. If it's low-poly, post as-intended shots (in-game if possible).
If there had been no quads at all in your post, I wouldn't have commented on them

... well, maybe something like "I hope that complete as otherwise editing will be a chore". I do see signs of good topology in various places in your model, but some areas indicate a lot of triangle thinking.
I just remembered another argument for quads in a game modeling context: face loops make for good triangle strips. That may not be an issue in your engine, but it's something else to consider.
Hmm, actually, I'd like to see your model with flat shading. I find smooth to be distracting sometimes, even if the end result will be a smooth shaded subdiv model.