I'm enjoying it so far. It's a nice mixture of the RTS games I'm used with a very FFT feel. I can't think of any other game that combines quite the same elements as this one.
I have to say that the graphics look a tad sloppy at times and while I'd be tempted to write it off as system limitations, I didn't see the same problem in FF III DS, which seemed to be a much larger game and more graphically intensive. You can also see some laziness in sprites that were obviously stolen directly from FFTA (though made to look much more grainy and awful). Music is also a direct rip from FFXII, though much worse in quality.
That doesn't matter so much though. I'm no graphics whore. It's expanding on the FFXII story (which was weak to begin with) in a good way (unlike the way FF X-2 did so). Overall, I think it will be a wholly enjoyable experience.
I think we often set out expectations too high and judge games only as they compare to other games or (worse) to our favorite games. While that is a reasonable way to look at games, you have to look at the other end too. There are far worse games coming out right now than FFXII:RW. I think this one is definitely worth owning.