Anthem D2V 3D/P5 or Cary Audio Cinema 12/7.250

If mainly movies are you deal, then the S150's should serve most just fine, and do well in low ceiling applications.
As for Oppo bypass, fer chits and gigglies, you can always try tinkering with bypassing the external pre/pro, going straight to amps, yes. But, you will easily find that you'll find no significant upgraded mid-range, top end, or open sounding upgrade doing this with your M&K S150 series, assure you! Plus, you can guarantee a downgrade in ultimate dynamics and processing options, plus convenience and ergonomics. Stay with the processor (then you can also A/B compare till your hearts content, FYI).
That said, I think the EQ in the anthem and overall refinement it offers (gunna be about as good as you'll hear through those midfi HT speakers -yes, Midfi..I sold em many years), will do more than fine for your needs. And you WILL NEED the EQ in all but the most ridiculously over-sized, high ceiling domestic home spaces, if you care about flat accurate sound and response - Absolute necessity, yes.

You should probably also consider the Emotiva XMC-1 with Dirac room correction. $1999, 30 day in-home trial, 5 year warranty.

https://emotiva.com/products/pres-and-pros/xmc-1

-RW-

Rlwainwright, Did Emotiva actually ever end up getting shipments out on any of these processors, after all of these years?!!! I remember back in 2008, being on a waiting list for the UMC200, er whatever, and NEVER GOT A RETURN CALL OR EMAIL BACK FROM EMOTIVA, stating that my unit was available for purchase?!!!! Talk about stellar customer service. And it was AT LEAST 2 YEARS OR MORE, that I remember being on that list! Anyway, it was silly bad business from them, from what I remember. Amazed they're still in business, honestly..
That said, so you think the bugs are all worked out, and the product is worth the money you can get em for, really? Also, what's it sound like, comparatively, across the board? The EQ really any good? Just curoius. Cause I've lost touch with that line