Lighter 'Mechs should be inherently more nimble than heavier 'Mechs, so the weight class idea seems solid imo.
At the end of the day, I would like at least a bit more lift for a given number of Jets on a 'Mech of a given weight (for instance, a Grasshopper with four as opposed to a Summoner with its five), especially for something as heavy as the Highlander.
Maybe, not being competitive, I do not understand why the HGN and VTR needed to be nerfed the way they were. Assault-class JJ in general seem to be pretty well useless (most probably the Class I versions in particular) which saddens me; my Heavy Metal can barely get on top of most short structures, despite having all five of its JJ equipped, which makes me wonder why I even bother jumping.
...Although at the end of the day, just having the Jets is enough, particularly if you miscalculate and end up falling a long ways. Breaking the fall, as poorly as they do at these weights, is better than taking a full "H" of fall damage.