Okay, here we are. It's a spreadsheet comparing the numbers for Super Robots and Real Robots, sans things like Great One (because that has so many size consequences and conditions involving division etc. that it'll take a while to sort it all out), but that seems to lean heavily towards being a trap defensively (Great Plate: +4 Nat AC, half dodge AC works out to a net -2 AC over the course of a build, plus Colossal has a -8 AC penalty in and of itself to get the most HP)
The general trend seems to be: there's not really room to customise the base Super. You take Plating
and Agility else you fall behind, that's it. Same with targetting--unless you've got the Dex/Str to compensate, you're going to fall behind the same-tier Reals without taking both of them. After Real II, it tends towards the base Real mecha containing at least one thing with equivalent defences and AC before you start digging in the arsenal stuff, and the high-tier arsenal upgrades totally throw that one out--+7 Shield AC is pretty much equivalent to the Super getting an extra 6 pilot levels of upgrades for one. If you both take one of the same upgrade, then the Reals are still winning there.
Real Robots flat out win the weapon war, no contest there. Supers can stack damage, that's pretty much it, and don't have the same monstrous base damage dice to pull on. It only gets more out of whack later on--the number of options there
before arsenal weaponry is... silly.
The Alteisen Reise is completely out of scale with literally everything else.
So... as it more or less works out, Super Robots don't have much choice on customising statblocks, because it's hemmed in to such a specific area that you fall behind if you don't invest everything. If you actually want to
customise in that sense--more tanking vs more dodging etc.--without actively making yourself worse, you're better off picking Reals because there's actually room for some variety there--HP and DR aren't intrinsically pinned to having the requisite AC.
That, and any variety in battle tactics pretty much requires it because every Super Robot attack consists of "run in and hit it in melee". Appropriate, but not room for much variety.
EDIT: Fixed the Vahlhawk line as that was edited after I'd done that tier. <_>