My contribution.
I had a Mid 2010 Macbook Pro with a Matte Display for 2 years. It was beautiful... I hated the glossiness of the regular MBP for the exact same reasons. I didn't need to see my own face when working.
Now I have the rMBP (I was precarious to do so as I didn't want the same issues as you, but I took the dive) and it's fine. It's not matte, but it's downright close.
I must add that I haven't put myself in extreme situations, such as watching a movie sitting in the sun (which in these conditions, may I say, I could see my face with the matte version too). I'm just saying as a previous Matte user that has the same worries as you, I would believe in the glossy rMBP screen's capabilities.
In fact. It's more of a Satin display. If that makes any sense whatsoever.