I've got mates with tru-track front and rear on a 300Tdi110 and a D2a. Both are really happy with them.

I've got ARB air lockers, which came with the 110, but if I had to spend money, I'd get the tru-tracs front and rear. Cheaper, less complicated, less likely to fail, positive traction all the time....

Neither has reported any steering issues. On the 110 it actually reduces straight line vagueness.