I have played with everything… well not really, but mainly controllers, keyboard, hitbox, and stick, and everything has pros and con.
For my personal insight hitbox, I mean it does give some edge being that pianoing motions can be quicker and more accurate than a joystick. The smaller buttons may allow you to move from the punch section of the buttons to the kick section of the buttons and vice versa. I personally don’t like the smaller buttons, since they kinda cramp my hands a bit, but that’s just me. quarter circles and dragon punches are also easier imo to some extent on a hitbox, but the half circles kinda get to me when I played at first (note this one is when I play on keyboard and I set it up kinda like a hitbox when I do play on that). Hitboxes and keyboards kinda feel really weird at first and would take a week or maybe even up to a few months to learn and get used to depending on how well you learn, at least to the same level that you were with your stick. But even then, I do prefer sticks in the long run, sticks just feel more engaging imo and although I can play CvS2, Guilty Gear XX Accent Core +R, Street Fighter, etc. on hitbox and keyboard at the same level as I do with a stick. I absolutely can’t, for some reason, play MvC2 on anything, but a stick.
Pros on the hitbox:
-Buttons only, meaning possibly a slight edge on motions and movements in terms of accuracy and speed.
-Easier to store in a bag or backpack… since no bulging shaft or balltop to make it stick out, but that’s what the JLF Link is for, sadly that’s JLF and LS-32 only.
Cons to the hitbox:
-Not really in the common market, so more people will have sticks and if your hitbox runs into some issue during a tournament, then you may be out of luck to some extent when trying to borrow a controller (I know someone who ran into this issue at Evo actually, since he wanted to enter the MvC2 tournament, but no one had a hitbox for the game), but this is minor with preparation.
-Relearning a control method, not a big deal if you’re willing to put the effort into it.
For those pros, I’m not sure if it’s worth the time to relearn a control method, but I have no say to that. For the possibly better execution, I mean people like IFC Yipes had some of the best executions in fighting games using a MAS stick, but I think he uses P360 with his back in the day (I think). Same goes for Sanford Kelly and Justin Wong. They were more than adequate enough to dominate and have some of the best executions with a stick. Khaos for MvC2 used a stock JLF and Sanwa buttons, and he has godlike execution as well. The point is that although a control method may give an edge, the best thing and most important thing is to make sure you are comfortable when playing and to make sure you can execute what you want properly. I’m not saying all parts are equal and there’s no point of changing from stock, since if I did, then I would be a massive liar with all my sticks being far away from a stock JLF or Hayabusa at this point. But the best thing to do is just try it out even for an hour and see if it may be your type of thing and if not, then stick with what you are comfortable with.