UB's is one chop. It's set it and forget it. Then start 12/12 about 2 weeks later if you want speed. Works wonderfully.
MLing you have several cuts to make depending on how many tops you want. Hence more veg time. You'll have a week or so between each cut.
Both methods are great. Just depends on how long you want to wait.
I've done both outdoors. Had a summer long veg with UB and had 4 big ol' fatty colas. Had to tie those suckers up. I do it with guerrilla plants.
Also MLed a bunch of Guerrilla girls this year. They stayed short and wide. Was kind of a bitch keep up with them. Especially since 90% of my visits were during night time hours.