A couple of minor problems I've noticed with my Trekking bars (non-LHT). When pedaling out of the saddle my knees can strike the shift levers of the SRAM X7 shifters. I'll probably eventually go to grip shifters.
When doing some tough downhill in the dirt loaded for camping and clamping down on the brakes hard, if it's rocky and rugged you aren't getting enough leverage to control the bike well with the hands that close together. Of course I should have avoided that road in the first place but that's another story.
Love the Trekking bars though.