Highlanders were my first assault chassis, and I used to love them. The 733C can still wreck face in public que as a AC20 (or 2 UAC5's, your choice), 2ML, 3SRM6 brawler with STD engine, but post-quirk the Stalkers are a better choice overall- particularly with the mastery pack idea as Misery>>Heavy metal.
If you go highlander, my thoughts:
Put 1JJ on it. the two tons are worth it to get over rocks and silly little humps. Also can help slightly in brawling to turn and spread damage some- just don't count on it to do much other than that.
Except for LRM or offbeat builds, avoid the XL. Because of the low engine cap you get mostly a weight savings rather than a speed boost that you would get with the Victor, Battlemaster, or Banshee with their high engine caps. Once you put endosteel on the mech, you won't be able to use all that weight savings because you will slot out before you ton out. If you take off endo, then your weight savings is only about 5-6 tons, not worth the lowered robustness due to XL. I lost side torsi pretty often in mine when I ran brawling XL builds.
Low slung hardpoints are a pain. You will shoot a lot of dirt at first if you are used to ridgehumping. Get used to the low slung cannons.
Overall, the Highlander is only a really viable mech in a couple configurations and is in need of some quirkage to be a first-rate assault again.
Hope that helps.
Edited by BigFatGator, 03 January 2015 - 07:20 AM.