Wow, your story is almost exactly like mine
I started TRing in March '09, switched to brazilian in October '11 to try to transition, and now here I am.
First, do you have a picture of your hair now? Which TR system did you get done (Liscio, Yuko, etc.) - they don't all work as "well" as each other. For example, I had Liscio, which is considered the "best" AKA my hair that was treated was completely poker straight and would be forever.
My hair seems to be curlier and was a lot frizzer than yours, so that made it VERY obvious when my roots were growing in. For that reason, I decided to chop it. I expected that it was going to look awful and I'd just have to deal with it while it grew out, but actually I ended up with a really cute cut that I've gotten soo many compliments on. What my stylist did is cut off the TRd ends everywhere but on the sides, where she left it a little longer and angled around my face, so that it's not just a round puff on the top of my head (would be cute on some, but not on me LOL). So I guess it's an inverted bob, with the back curly like you saw in my other thread, and the sides are wavy/straight. What I do to avoid using heat (since the roots in the front still grow in curly), is I tuck my hair behind my ears while drying so that it turns out smooth and wavy, then gets curlier as it goes to the back. It's hard to explain and I'd show you a picture, but I'm a little leery of posting pictures of my face or other identifying details online.
Anyway, long story short - being that your natural hair looks a bit tamer than mine, you might be able to get away with growing it out. But you might be pleasantly surprised to find that you can cut it and have it look good. I'm going to respond in my other thread the particulars of my routine