I add my congratulations to paying off the loan. I probably shouldn't opine hear, since I haven't heard the specific speakers that you are discussing, but a few thoughts.
1) In general, I think a set from the same manufacturer works better than a mishmash of different companies. I have 2 HT systems in my house. One has a speaker smorgasbord, the other all from one manufacturer. I definitely prefer one from a single manufacturer (the AVR in the two is the same, more later), as one can actually hear not subtle timbre mismatches when playing music in the other one. For video content this is less important.
2) I don't know if Denon is using room correction software in their AVRs, but I use Anthem AVR, with their Anthem RC, and this has made a big difference in both systems, particularly in the bass. If you don't like RC you can disable it, but I think it is a valuable feature