Question: PCNC 1100 vs 770MX ??

Please hear my use cases out before weighing in.

So I’ve been pretty dead set on a 1100 but was recently being told that a 770MX might fit the bill. I’m mostly constrained by cost. really don’t want to spend over 15k (all prices assuming ATC, hard requirement). I have a few 1100 options at that price, but haven’t really considered the 770MX. So why not a 1100MX? That would be great, but I have a hard time swallowing 25k for one when I could get a used Haas for that, which we all know would run circles around a Tormach. I know I know, that's a different discussion.

My use case is as follows:

1. Cutting steel, brass, bronze, cast iron, and maybe some aluminum. Probably 50% will be steel, so I really want that rigidity. I don’t need crazy tolerances but really would prefer <.005 or .003 at a minimum. Getting tigher tolerances to achieve correct press fits would be a nice plus. Going slow is fine. Ive generally understood the 770 to be far better suited to aluminum since its a lighter, less rigid casting yet has higher speed spindle. I’m way more concerned with accurately cutting steel.
2. I will be using rapidturn. I already have it, and I will be turning things up to 11” in length using a tailstock. More than likely will leave RT on the bed as I have lots of turned parts to make. Not super sure this will fit nicely on the 770 bed. Am somewhat familiar with Tosa tool. Haven't exhausted assessing their catalog, so feel free to chime in here.
3. Lots of parts will have tapped holes. I’m not daunted by thread milling, but wondering if the speed of rigid tapping on MX is worth it.
4. Most parts won’t exceed 11” in length so I’m generally okay with the size in that regard. I will have to make plenty of fixtures which will be slightly larger.
5. High mix of parts. I'll be making lots of parts in the range of 4-12 in quantity. Should the business grow then of course higher quantity batches, but I'll address that when I get there.

So, in a nutshell, does the new 770MX casting with BT30 holders provide the same rigidity an older PCNC 1100 does?
Thanks in advance.