I got my SDOJ today (regular edition). The port menus are the same as the MMP/PS double pack, even the replay menu (fast forward, etc) is the same. You can't enter any initials. Disappointing. You can turn off the voices in any mode including Arrange. If you adjust the screen size in Arrange the side faces and whatnot disappear, replaced with the wallpaper of your choice. I really like the shop system and the gallery. Nice added touches their earlier ports should have had.
The Arcade HD mode and Ver 1.5 modes are quite challenging, though Novice is as easy as usual (I 1CC'd it with C-Laser on my first try). Arrange is neat, but so far, just a nice diversion in my eyes (typical for Arrange modes).