A lot of this depends on the rest of your rig. There is no one best way.
For me a few things made the difference with each.
First, tame the highs. As more seem to do all the time, I use beam blockers but only on the top half of my 4 x 12. Its the right mix of smoothing and splash IMO. Next, I trust my ears and not my eyes - aka the knob numbers - when building a tone. So many people struggle with this simple but profound idea built on bad habits picked up as kids with crappy gear. Last I rarely run the tone on my guitar wide open, its on 8-9 instead of 10 much of the time. I find a small number of subtle changes works better than one drastic change, but thats me with my rig.
Low end girth is not a problem with a good 4 x 12 size cab. I'm not a believer in the magic 2 x 12 boxes some speak of... they get the job done to be sure, but nothing defeats simple physics for tight low end. To me the right 4 x 12 resonant point is the key. 2 x 12s always got wonky or woofy in some particular middle low frequency that I had to fight to tune out or tune around. Much less of a problem with the bigger box cab even with only 2 speakers in it.
The Ace head I use also puts out tons more bass than I'll ever need and I do play drop d flat tuned modern metal quite frequently. Plenty of chest punching, pant flapping glory and little flub. Changing my pickups out from A2 magnets would tighten me up more I love the sweetness that the A2 gives and I sacrifice a little tightness for it. But really, to me this is much more about the right cab and speakers. Don't assume Mesa makes the best cab for your personal sound. I didn't.
-P