For every Denon fan you will hear from, you will also hear from a Pioneer fan. There are many of us too.
I would keep the Pioneer SC-61 unless you are planning to spend more on a Denon to get you the newest version of Audyssey. Great price BTW for a new SC-61. MCACC does a very good job and some actually prefer it. I have had four Elites so far and no problems with any of them. Also, the new Pioneer Class D3 amps are 4 Ohm rated and have been extremely well reviewed and received. With your 4 Ohm ML's, I would think this is something important to you. Good luck though in whatever your decision is. Ultimately it is your system; not ours.
Marantz PM15S2 LE, Oppo BDP-103, Simaudio Moon 100D DAC
VPI Traveler V2 with an Ortofon Rondo Blue and Simaudio Moon 110LP, Technics SL-1400 with an Audio Technica AT-14sa and Pro-ject Phono Box S
Dynaudio Focus 260's, Rel T-1 and a Panasonic TC-P54S1.