So when I first started removing my beard i went to several electrolysis centers that are familiar with trans patients.
Both recommended starting with laser first to reduce the amount of hair. Most of my facial hair was dark at the time.
Anyway the place I chose, offers both laser and electrolysis and has a large transgender client base.
Since May 2014, I've had 9 laser sessions full face and neck (1 every 4 weeks) and in between the full face sessions I've had my upper lip and chin done (now at 8 sessions for that).
If I let the facial hair grow it's now more gray than dark . On my neck there is almost nothing but gray hairs left. So, I started electrolysis last month.
After 2 one hour sessions (only half of each session was spent on my upper lip). My electrologyst feels that my upper lip will have been fully cleared with another 20 minutes or so. Please don't get me wrong, this is only for the initial clearing. Then there will be more for regrowth (as you know hair grows in cycles).
YMMV, but if your hair is dark then I might suggest that you could try laser first.