The room size is 2600cuft and the usage is 70% movies. 28hz is fine for most (but not all) music but for movies I like deeper bass than the Jamo offers. Yes I'd rather see the OP buy an Outlaw LFM-1 Plus or a Hsu VTF-2 but that's over budget and the little eD should be able to handle 2600cuft and do it more effectively than the 10" Hsu or eD that the OP was originally looking at.
The D6 Sub is THX Ultra cert & is excellent for movies. It would not be certified Ultra if performance was only down to 28hz.
Please see my post/comments that I linked to the AVS Forum thread about the D6 in the $500 sub thread. It's post #9 here:
http://forums.audioholics.com/forums/showthread.php?t=73447 The guy loved it for music, but thought movies were lacking. Turns out it was his placement and settings after another forum member came over to help him do a proper setup.
I believe that the Jamo website specs as well as the Amazon specs are incorrect. As is Vanns website, which is calling the D6 THX Select. I remember the Jamo product sheets and website showing both he D6 & D7 having identical specs except for he Ultra2 designation which, at the time these were released, was supposed to show a "theater only" speaker, ULTRA, & a theater + music product as ULTRA2. Perhaps I'm recalling that wrong since the Ultra cert has been gone for so long, but I'm almost certain. Regardless, we've used these a bunch in previous systems and it's a beast of a product. I'm excited to get our hands on the new D 600 SUB which is a 15" Ultra2 @ 1600 watts.
Lastly, this is where just reading a mfg specs & not using sense can end up hurting you. Manufacturers, particularly ID companies, know most people will buy on spec.... No different than someone at BB walking through looking at receiver fact tags for the one with the highest watts. As Zumbo eluded to, it does not make sense that a 12" 200 watt sub would realistically hit 20hz to a usable degree in any sizable room. Please look at the post I referenced above and click through to the AVSF link I listed there. They post graphs of two D6 in a 3500 cubic foot room.
It doesn't matter to me which one anybody decides to go with, but to say that the D6 is not designed for movies does not do the product justice, so I wanted to add some food for thought. Thank you for reading!