Not MtF here, but due to out of whack hormones my entire life, I could only grow patchy facial hair and, as it was dark, it just looked like I had a weird skin condition when I'd shave. Makeup couldn't cover it either as most of it was jet black.
I tried laser first, as it was cheaper, but the problem was...it didn't work as a
permanent solution.
It wasn't super painful, it was fast, though the smell of burning hair was unpleasant, but it straight up didn't work as a permanent solution for me.
The hair always grew back, even after the full set of treatment, it always came back. The only response from the treatment center was, "Well, our literature does say it only works for 85% of people. You must be in that other 15%. We also don't guarantee permanent removal, just a 'reduction' in growth." and I was basically out $950.

The ads heavily imply that they guarantee permanent removal, but if you read the fine print, most make that 85% mention and mention that they don't guarantee it's
permanent or that it's a removal. In the case of the company I went to, which was a reputable one I won't name, the only guarantee they had was a "reduction in the appearance of hair growth".
Most companies only give a "2 year guarantee" of no regrowth at best.
After that, I got a bit discouraged and just stuck with shaving and having weird 'dark patches' on my face, then decided to go with electrolysis.
The cost, at least where I live, was comparable to laser so that wasn't an issue for me.
The pain of it varies though. On my cheeks, jaw, neck, sides of my upper lip, and chin it didn't bother me too much, it was just like someone snapping a rubber band on my skin then plucking a hair.
Under the nose, however? The words I'd use to describe that pain level are words that are all forbidden by the rules of the forum. Even with numbing cream I couldn't ever stand to have her do all of it in one go, and I'm forever grateful that I didn't have too much dark hair on my upper lip. Now and again, I let her take the darkest ones out but, if it bothers me, I just wax instead.
I have a pretty high pain tolerance too, and it's just--really painful to the point that I prefer to wax my upper lip if I feel like there's too much dark hair there. Still, it's worth trying out to see how you tolerate it.
A good electrolysis clinic will walk you through the process and do a couple of 'test zaps' in various areas you want done to give you an idea of what it feels like and to let you gauge whether or not you think you can handle it.
It's been about 2 years since I started and I just have one little patch of about 50 hairs on the left side of my neck, just under my chin, that are being stubborn about dying. They get weaker (thinner and lighter) with every treatment but WON'T JUST GIVE UP AND DIE YET.
The lady I see works primarily with MtF clients, so she's well versed at doing electro in the full body sense; she's told me she's even done ears, toes, and nostrils (I don't see how anyone can endure that, but apparently some people can!) in addition to the more usual legs, chest, arms, shoulders, back, hands, and face.
She also told me she did her own electrolysis, including under her arms.
I did ask her about doing nasal hair once, as I was curious whether it was a thing or not, and she said it's possible but most people can't handle the pain of it very well and it's tricky to do. She does, however, offer waxing services for people who want less hairy nostrils.
The way she described it was getting the wax on the cloth, twisting it, poking it up the nose, letting it set, then just yanking downward; she swears it doesn't hurt, but said it makes most people sneeze.
While that isn't permanent removal, the hair does tend to come back thinner and lighter with each waxing.
I have not, however, tried that myself and may have cringed when she described doing it to herself.
The only caveat on electrolysis is that it
is permanent as it kills the hair follicle so, down the line, if you ever decide you want to grow your facial hair out again, it won't be an option.