I have used the Elecraft T1 with my FT-817 during back country canoe trips in Northern Ontario. It has performed very well. Even without the FT-817 control cable it tunes with just a couple of button presses.
There is nothing wrong with the LDG 817 tuner, it is just bigger and heavier than the T1.
The only reason I won't be using my T1 anymore in the backcountry, is because my Elecraft KX2 has the built in ATU, which is also excellent.
Gordon VE3JSJ