You might get more help at the Meridian Hitchhiker's site: http://www.meridianunplugged.com/
I had a Meridian G-68; and upgraded to a used 861 v4.2; and use the Sony 5000es Blue ray player. The blue ray handles the new codecs with internal dacs; and I use the analog out of the BD into the Meridian processor...most of my BD discs however are still DD 5.1; and not the HD audio...the G-68 is already configured for 8 channel analog in; and is a good processor; with the benefit of a zone 2 control, and easier use and programming. The 861 is a bit more musical on my music server; but using it for zone 2 was more challenging. A high end store where I live is using the G-68 as its processor on a full Meridian speaker line up; with a great projector and blue ray; and it sounds fabulous...
Don't know much about the Meridian HDMI converter switcher which is now out for around $2800; it splits the audio and video from hdmi signals; as the processors don't handle hdmi.
Much depends on your budget; and if this is only used for HT; or combined HT and audio enjoyment...cant' go wrong; good luck
Kal; can you elaborate on the virtues of the hd621? is there a review somewhere I can look at? Not sure at that price point of the advantages for us Meridian users....
I'm running my hdmi out of BD into my TV directly; will this improve my video signal as well? problems with extra cables? have you noticed issues regarding quality of hdmi cables to hook up this box?
any help would be appreciated.