Its quite a decent game, its not as engrossing as the original FF7 though... maybe its because I am older... I am also finding it too easy...
As for the DMW thing... its seems a crap idea to me, but I think it is a way of randomising between the limits/summons/boosts/leveling up... In one fight I got it about 6 times in a row... not sure how it decides when you get it...
and I'm not keen on the idea of having no maximum HP/MP/AP... (when you get HP boost on the DMW, your HP goes up even if its already at maximum)...
one thing to remember to do is the missions you can access in the triangle menu at save points.. some of them are quite challenging...