My experience (upper jaw impaction and lower jaw advancement and rotation with extraction of lower wisdom teeth), if it helps..
I told my employers about the surgery before I was braced, and ended up having the surgery 16 months later than expected, after 28 months in braces. They asked me to arrange, if possible, for it to happen in August, as this is a quiet time for us at work - and fortunately, that's when the surgery was.
I'm a civil servant so would be eligible for 6 months paid sick leave anyway, but I planned to take 2½ weeks off work. As it was, I was checking e-mails from home a week after surgery and went back to full-time work after 1½ weeks. By that point I'd stopped napping during the day, had stopped drooling, and could drink from a cup without spilling it, so I thought I was ready to go back. For the first few days back @ work, I was absolutely knackered at the end of the day, and had no energy to do anything other than eat some food and then doze off in front of the telly until (early) bedtime.
What's most inconvenient at work is that I cannot eat with dignity at the moment so am having to drink Slimfast and smoothies instead of eating food. I save dropping it all down my chin and front for the privacy of my own home
I am not finding speaking difficult, but I am not speaking very clearly because I have alot of elastics on (so can't open my jaw much) and my lower lip is still frozen. I can be understood, but it's definitely not normal speech. I've got a diagonal elastic across the front of my mouth that vibrates like a kazoo when I try to speak
It's harder to speak with a splint in than without one, so find out if they're likely to leave that in place after surgery (some do, some don't). Some people are also tight-banded shut which would make speaking tricky. I had a splint for a week but have only had guiding elastics, not banded shut or wired as some people are.
I haven't really had much pain, other than a very sore mouth in places where the swelling forced the inside of my cheek to rub against some of the surgical hooks on my molars - salt water rinses sorted those out after a few days. Not any deep-seated bone pain, though, nothing like that. It has definitely been uncomfortable rather than painful.