Folks, I'm looking at a Kwaiken and am not knife literate enough to understand the differences between the flipper and the disk opener. Is it just a matter of preference? Also, I've seen reviews stating that at least the early Kwaiken were not easy to open and had tip protrusion issues when closed. Was this a problem cured in the current ones? Was it specific to the disk openers? I am leaning toward the disk opener just because of familiarity. Any help would be greatly appreciated. Thanks, Joe