As a long time BT fan (I've played the board game since its inception), I find ToS to be a *major* improvement of the BT concept in all fronts - ok, no vehicles and infantry of any kind, and no artillery and whatnot, but then I don't really miss them. Good for the books, but the game should focus on 'Mechs/Titans - the whole point is to picture yourself piloting one of those steel behemoths against a similar foe, not facing them on the ground like a common soldier! Wargames deal with infantry and tanks.
Anyway, like I was saying, two of the measurement scales used in the definition of Titans in ToS are less than perfect IMO: the height scale and the weight scale.
As for heights, ToS has improved the general 2-level (~12m) tall 'Mech to a categorized height system, depending on weight class and chassis. This is a great concept, much more realistic and with more impact in LoS. But I would have implemented it differently. I would have given all the chassis in the same weight class the same height. Why?
First, because that would allow reducing the span of chassis heights, going 6-8-10-12-14 or 7-9-11-13-15. Having an assault be 3 times as tall as a recon is not a good model IMO, even considering the weight difference (I'll get there soon) - double seems a lot more logical. This would also make rivers and swamps and the like work more logically, since the heat dissipation increase you get in a recon waist-deep in a river is the same as a barely ankle-deep assault - even considering relative immerse mass. Not only that, the "martial arts" problem would be considerably reduced - a 6m recon kicking/punching or ax'ing a 19m assault in the head, heh; and charge damage distribution too.
Second, the taller chassis within a given weight class are generally the best, since they have more slots (and therefore internal structure) and are faster. Being taller, even by just 1m, is another advantage they do not need - important in LoS, scan height, lock acquisition,...
This would have some impact on the game, namely on LoS and height defensive modifiers.
Titan weight is where I think ToS incorrectly strayed from BT. Though the horde of available systems and need for more armor (which make Titans more solid entities than 'Mechs IMO) require more tonnage, again the weight span deviates from solid models. The weight limits have the same relation (doubled in ToS relative to BT), the weight *difference* between the lightest and the heaviest chassis is also doubled! That's a huge difference.
Not that this has a great impact on the game, by cutting the weight of all equipment in half you'd get a 'Mech out of a Titan. Probably only charges would have to be tweaked to compensate the decreased tonnages.
Notice I only mentioned Titan related scales, not terrain related. That's another story, but I think those fit very well the scheme of the game
Of course, these points only surface when you actually *think* about these things, in a logic approach. But we all know this is a game, and as such ToS ROCKS and beats the cr@p out of BT