This game is awesome, but it reminds me how bad I am at fighting games. Some of the combos are so hard to pull off. Maybe a fight stick would be easier than a DS4...
If you've never bought an arcade stick---be warned: there is a learning curve with it.
I remember when I first bought my TE2 from MadCatz thinking I was going to be the bomb at SF4 once I had it. WRONG! It was like taking 20 steps backwards. I had worse execution right out of the gate.
I looked up a few online guides/videos of how people held their sticks, placed fingers for buttons, etc. I hit up training forever in SF4...and I still couldn't get the motions I needed to come out like I wanted.
I was about to just go back to pad, then I saw an octogate for the stick was like $5.00 online and was reading some people had a WAY easier time using that then stock square gate. Figured why not try it and rule everything out, and sure enough that was my ticket to way better execution.
Not long after I was doing whatever combos I needed consistently(minus 1 frame link stuff...fudge that), and all was right in the world.
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TL;DR- A stick won't make you better at fighters unless you are ready to commit serious times to it and the game of choice.