Still not convinced.
I mean, what's the point to have a built-in decision system if you know who's gonna win before the dialog ? "Eh, looks like a Bluff situation, well, fuck that, I'm out of luck..."
Either you can chose your approach and the dev's point of view is the answer or gives bonus (which can be very well done or very stupid) + highest stat wins or the appropriate approach is built-in and, well, highest stat wins even more.
In my point of view, even a socially inept Biodrone who fails at romancing in Mass Effect should have a very small chance to win a Charm check against George Clooney with a lucky natural 20. Maybe it's a little bit stupid (then again, 5% is not a lot, right ?), but it's the only way to keep things interesting and for this system to achieve its goal. Else it's just gonna be "ok, bluff you win, intimidation and reasoning I win" => what's the point to have a discussion then?
I just want to hear "YES, WE'RE GONNA HAVE SKILLCHECKS WHO MAKE (possibly huge) UPSETS POSSIBLE" to be happy. Everyone should have a possibility to win every check in order for these discussions to not be a tedious part that people are gonna rush not giving a single fuck...