I'm in the same boat, but I've pretty much settled on a J360 because the only games that interest me are STGs. Cave pretty much said that Espgaluda II was the last region-free game for the time being. So unless Ketsui and Deathsmiles II get picked up for localization, it's unlikely that you'll get a shot at playing them. If Cave stands firm on their region-lock policy, then the same applies for Dai Fukkatsu and Pink Sweets, if they ever get ports. But then again, if these games aren't a priority for you, then this doesn't matter. Ketsui was the deciding factor for me personally. Another thing to keep in mind is that games released in the Asia region are compatible with a J360, by my understanding, and are sometimes released with English language versions. So there's a backdoor to try if a particular NTSC-U game isn't compatible.
