...and now that we've gotten the SHS, 26kph Mauler out of the picture...
My choice would probably be the Executioner. I'll admit that I have the D variant coming with that ridiculous 7E arm (that
is the D, right? I forget which variant gets what pods at the moment

), but even without it the Mauler doesn't do a lot that the King Krab hasn't been doing for a while now. It comes down to a preference between arm or torso ballistics, or a preference between flat-n-wide or tall-n-skinny. There's a few interesting Mauler variants - the 6E model with armfuls of beams could potentially prove a very dangerous enemy - but overall the Mauler doesn't add a lot of new to the table. It's going to be good, don't get me wrong, but it's a big, slow assault with lots of gunspace. I'm still going to be more nervous around Krabs.
The Executioner, on the other hand, will have unprecedented mobility for its size. ~71kph stock, and while everyone will scream about how it has the same overweight-engine issue as the Garfayle, the Executioner's 380XL weighs
six less tons than the Garfayle's 400XL. That right there is the Endo Steel the Executioner doesn't have. Four jump jets - which will admittedly be of dubious value, judging by Highlanders, but still - and the potential sprint-button M.A.S.C. provides means this is a 95-ton assault 'Mech that can (temporarily) outspeed a number of
heavies. Even without the D variant you can get 8 energy on it for beam spam, and unlike the Garfayle it actually has the spare weight to do a class-20 AC and a quad or hex set of infighting lasers without wanting to die.
Now, I'm being optimistic here because I dearly miss my Victors and want the Executioner to be this amazing blend of fast fatness, but even if the Executioner is as average as the Warhawk overall, it'll at least be its own unique brand of average. The Mauler, on the other hand, will be good pretty much the exact same way the Krab is good. So...take that how you will, I suppose.