Has anybody tried mixing bittersweet and semi-sweet chocolates? What were the results?

I have three 4oz bars of bittersweet and one 4oz bar of semi-sweet and since I'm inherently lazy I thought I'd mix them to make my Toba Garrett recipe of Modeling Chocolate which I need for her class at Cake Camp. I wanted to know if someone had tried this before and their results.

You should better go to get the exact ingredients of her recipe, I took a private course with her and she's adorable, but she's also very strict with her teachings and techniques so I would not change a bit of her instructions, imho.