I've owned 520's for over 22 years. Had three of them. This bike's rep speaks for itself. That said, the LHT also has a solid, no surprizes rep. Both will do the job well. No shaky shimmies here. The 520 might be better as an all around bike. Buy the bike that offers the better fit.

You keep coming back to the uncut steerer tube. I get it, buttttt, most likely once you get the bars set the first time, you are never going to touch them again. Why not go down to the LBS for a serious fitting on the bike and see where you stand? See if the bike can be set up to your liking. Neither of these bikes are custom fit. Both are off the rack-literally! The magic of customized hardware allows thousands of these bikes to be dialed in to perfect fit every year. If you can't get the Trek dialed in, well then, the choice just got a whole lot easier.

Good luck!!!!!!