Like Mentor58, I also have a LHT with a Tubus Cargo on the back and a Tara on the front. My LHT isn't fully built up yet (!) so I haven't been able to take it for a loaded ride but I can tell already that they're massive strong. They feel (especially the Cargo) like an extension of the frame. I threw 4 bags (Arkel GT-54 and T-28) on and it was just begging for a loaded ride. Despite not having any brakes yet, I was still tempted...
Oh yeah, and talk to Wayne at TheTouringStore.com, good guy! He'll set you up.
Maybe I should have just quoted Mentor's post?