I understand that sense of "cheating", but I have to remind myself, I'm trying to make a professional quality publication in my spare time. And I REALLY want to finish it before I die. So some things just have to give. And it's not like I couldn't do it without the references. I know I can.
To me, what separates the pros from the rest of us isn't that they draw so much better than us, it's that they can draw at least as well as us (most often better), but they can do it much, much faster, and can maintain consistency at that speed. The other difference is, it's their day job. They have hours to do nothing but draw draw draw.
I have a full time job, an Etsy shop, other art streams I need to maintain, a young family, plus a seemingly endless number of things pulling me away from the the meagre time I get to spend on my comic. So yeah, if using 3D references is cheating, I guess I'm cheating. But at least I'm making the comic I want to make. That's how I look at it at least.
Also, the quick and dirty traces I do are usually done in a matter of seconds and are made up of a single line, hastily drawn. When I think of the amount of sketching, inking, colouring and effects that go over that line... well, lets just say, I sleep fine at night.