I use a weed dragon occasionally.
I have one client where I can't use RU in certain spots around the property so out comes the torch.
The Weed Dragon works great, but you've got to be really careful where you use it and pay attention.
They make a smaller model that I want to purchase that is used for detailing purposes and is less aggressive with the flame.
The thing I like the most about it is the instant gratification I get when I use it to kill the grass between sidewalks and in gravel drives. A couple of times I've had to do a quick cleanup before a party or gathering and it makes short work of those spots when RU takes at least 1.5 weeks for weeds to die.