I Can't really provide you with recommendations here, but I do have a few things to say:
First of all the D Vine 6 SQ looks really sweet. (Designwise)
Then from my experience, you might want to be carefull as to where you're planning to install your HTPC. The one I installed in my parent's HT was enclosed with the rest of the equipment in a cabinet. Even with leaving the cabinet's door opened, the PC became boiling hot after just one hour. The problem that I'm trying to bring up is the following: a HTPC (like most PCs nowadays) needs a lot of fan power; which is obviously noisy, but helps you keep the heat out of the case. I don't have any experience with those new HTPC cases but they don't seem to provide much space for fans (i.e. the Dvine seem to only have 1 on the side and 1 in the power supply...) I really don't know if that's enough for a computer that should be running 24/7. Second thing is: I wonder how noisy/ silent those cases are. Like I said before, HTPCs are way noisier than a dvd player. An obvious solution would be to enclose it in a cabinet of some sort, but this setup will require additional fans (on the cabinet itself).
So anyway, all this to say, try to find information on the db noise level of those cases before making a decision. This is more important than the look/ design of the HTPC as it will drastically affect your viewing experience.
Hope this is of some help.
-Cascius
PS: this post might be a bit messy as I'm already half asleep.