People prefer the slide method, however I honestly feel that's the worst method because a slide input is relying on a sway to get an input, which is getting lucky at most. Not even VF players in VFDC do that.
Yeah, it feels incredibly awkward. Don't want to have to change my control scheme around for 1 character, and unsure about transitioning to stick for DOA. Other than that, Akira's a blast.
I use L2+ Square method.
First, I slide my thumb on Square and then immediately press L2 (kinda tricky to explain). I bet theres a better way to do it though.