Let’s compare; values from the guide
Dormammu: 13 startup, 17 recovery, tracks to air only, front, behind, or directly above
Wesker: 11 startup, 19-20 recovery, set distance to air or ground, crosses up at corners
Phoenix: 10 startup, 20 recovery, tracks front, behind, or air, air or ground, does not cross up at corners
Dante: 10 startup, 0 recovery, always tracks behind in air, crosses up at corners
Deadpool: 18 startup, 12 recovery, set location on screen, does not cross up at corners, malfunctions every 3rd time
As you can see, Deadpool’s teleport has the slowest startup, and second fastest recovery if you count Dante’s. Deadpool has the fastest recovery of all ground teleports.
Honestly, I think Dante’s teleports are the easiest to react to, even though he “recovers” the fastest, because he’s always going to cross up in the air. Wesker’s are easy to react to - even to punish, once you gain the matchup experience and get a feel for where he’s going to end up. Dormammu’s just requires you to be quick on the airthrow - if you guess the wrong direction, you’ll probably just hit him with a j.H.
Which leaves Phoenix and Deadpool. Phoenix is harder to defend because you have to react and recognize which side she’s on, unless you back yourself into the corner. Combine that with her fireball, flight + teleport overhead shenanigans, and you’ll basically be subject to dangerous mixup any time you’re on the ground.
Deadpool’s slower startup and limited use makes the opportunity to use the teleport fewer and farther between - but he’s a zoner, c’mon. If you can score a hard knockdown, you can run a teleport trap just as difficult to block as Phoenix. But if you’re trying to use Deadpool’s teleport the same way as everyone else… you’re doing it wrong.