Regardless of which subwoofer(s) you're running, deep bass is never going to be anywhere near flat "out of the box" without some serious EQ.
Is the Mini-Dsp and calibrated mic a miracle cure for bass?
No miracle cure, but it might be helpful.
I did the subwoofer crawl at 40hz with a db meter and found that the wall behind me was best, with the back right corner being the best spot in the room.
Just curious - you have two SB2000s, right? Where's the other one located?
I have a pair of SB1000s and I actually have the main speakers resting atop them. While probably not ideal, there aren't a lot of other placement options in the room, and that certainly simplifies some things. And since there are two subs instead of one, placement isn't super ideal.
I initially played with room EQ derived from MiniDSP measurements but ultimately abandoned that. Those measurements will vary greatly by listening position anyway, so unless you're willing to restrict yourself to a single listening position you'll have to average a bunch of measurements from different locations, which ultimately limits what you can do in terms of corrections.
(On the other hand, I'm really impressed by what Audyssey was able to do with the single sub in my living room, so maybe my REQ-fu and MiniDSP-fu were just weak)
As for "slam" I actually tend to feel that's more a function of mid-bass (like 50-100hz) than the really deep stuff. You could experiment with some boost in that region, maybe.