They also work great on the trail, IMO, but you don't want is set as stiff as you do in the desert/whoops.
They will give you better control and confidence in single track, especially if you have lots of roots and rocks. Front end washouts will be a thing of the past.
My first one was a WER on my '90 KDX. Moved it to my KDX250 and then had a Scott's on my CRE. Both Scotts and WER work great. Can't adjust the WER on the move like the Scotts, but the WER is out of the way if you slam into your bars.
Steering stabilizers are one of the best mods you can make to a trail bike, after dialing in your suspension. The only downside is the high cost, but if it helps you avoid an expensive crash, it can pay for itself.