You're right that you can spank any slope into shape using PEQ, but then you suck up PEQ slots. And (this is an area I'm really unsure about) the dsp processor doesn't have to work as hard with a simple preset slope. That may not be true or matter at all, but I've heard it come up before.
Compare to a minidsp with the advanced plug in where you have every slope available, AND you can over lay them with biquads. Yes, that's normally way more than a person needs, and the only simulation software I'm aware of that takes advantage of it is ACD (active cross over design) by our good friend Charlie over on PETT. I think soundeasy does it now too, which I'd love to get. ACD is a little bit awkward to use, and considering I've never actually had a need to use biquads, I haven't fully used it.
Don't forget, once this speaker is in the room, Chop may well want another 3 4 8? more PEQ slots. Thankfully it has 6 on the input side which can probably handle that with ease.