I think I'd rather be the gay dude. Not having a social life or sex, and having to look at my ugly self in the mirror would be just as upsetting as looking in the mirror with dysphoria. The other thing I should mention is that ugliness =/= no social life. Plenty of ugly people have friends. So you're handicapping the female choice big time.
Before everyone jumps on me- let me explain. This does not mean I am transitioning purely so I can be a pretty girl. I'd be content being a 4/10 so to speak. Dysphoria for me is very appearance and socialization related. If I just looked like an ugly man in a dress, and nobody accepted me, and I have no friends, I don't think my mental state would be much better. I'd still have dysphoria of a sort. There are other neuroses than GID- crippling depression would hardly be any better. At least as a gay dude I'd have something to distract me from it. Ultimately the question is one of happiness. Just being a woman isn't magically going to save you from depression, anxiety, and anger from lack of sex, low self esteem, and no social contact. Life as a women isn't all lollipops and vaginas! If you think this, you are hardly any better than somebody who is transitioning solely to be pretty!
However in my case, neither option is likely. I am not a gay man, nor am I interested in m/m sex. Also, I am fairly young and good looking. I think with the proper effort, I should be a pretty girl. I'm not sure the question applies- I'm not gay now. Would I become gay? If this is the case, is it unreasonable to question if I still have GID?
For me it's a question of going from a decent looking straight guy with GID to a (hopefully) decent looking bi girl without GID.