Yeah I feel AsCh is going to be far more successful in the west than Japan, and Daemon-x-machina is going to be wildly successful in Japan, but be very niche in the west.
AsCh is clearly the better game, but Daemon is a solid 7/10 for me, and will please most people that fit that niche. The free demo that lets you carry your data over was the best thkng Nintendo could do for that game. If you try the demo and like it, you will like the main game even more because you get a good idea of what the game is all about and you have access to many options as the game progresses. If you do not like the demo, you should probably pass because the demo is nothing more of the first chapter of the game so you would just be paying for more of the same.
But in Japan there are not really any real Mech games coming out anymore, so it was pretty much a sure bet that it would be a hit over there. I for one am having a blast with it, but I am loving it for what it is despite the faults it has.