The general impression is that the game still feels like Guilty Gear, which is definitely a good thing. Match pacing seems to be the same, and there is slightly more hitstop on hits which make hitconfirmation easier. As stated in the system info on the official Xrd site, the new roman cancel mechanic slows down time for the opponent, allowing the attacker to mount a stronger offense. Many normals, specials, and even movement(like backdashes!) can be RCed on whiff now. It seems that this was done in an attempt to make up for the loss of FRCs. The game is still played using the same 5 buttons that have been present since GGXX, but now there is a choice of 5 different button layouts at the character selection screen. Speaking of the char select screen, palettes can now be previewed before selecting them, like they are for Melty Blood.
Kurushii has started up an Xrd Video Posting thread on Dustloop. Even though recording videos of the location test was strictly prohibited, some people were still able to sneak in some footage.
Here is a list of sites currently running articles on the location tests, with lots of nice pictures.
Radio Kaikan (tons of images)
Dengeki 2 (2 pages)
Dengeki 3 (3 pages)
An MMCafe user also wrote up a brief report here.
The Dengeki articles also have a brief interview with Pachi. Even though FRCs are not in the version of the game at the location test, it is hinted that they be added to the final game, as he mentions that there could be more RC types than just red and yellow. The match HUD still has the meter in 25% increments as well.