Dante is completely unsafe on just about everything. If you block anything he does it leaves him wide open. Sadly all of his combos and super confirms are off of 2 unsafe moves and his counter, so it's really easy to know what he's going to do, especially since a large part of his moveset only becomes useful after he's already started to combo you with his 3 unsafe combo starters.
Sackboy was already a gimmicky character, but now he's a gimmicky character that doesn't really gain any AP. Sure, he has AP burst combos, but they require he be in close range when he is very clearly a keepaway character and tends to lose at close range to most other close range characters. Unfortunately, his ranged tools don't give a whole lot of AP and his supers are now quite expensive, so most often he'll either have to use level 1 (Which can only be confirmed off of shockpad, but the timing and spacing are pretty strict), or level 2 which can only net you at most a single kill against each player and while it's good, it's still not the hardest thing to avoid. His level 3 is pretty ridiculous, but the problem is that he really shouldn't be hitting it at all anymore.
Spike is so very close to being a good character, yet falls just short of it.
His supers are incredibly subpar, with only his level 2 having a decent hit confirm (I hear he can hit confirm level 1, but only off of the car, grounded banana or cannon at point blank range, otherwise having to use it as an anti-air, punisher or just mindgame people into it). His level 2 is decent, but sometimes glitches and doesn't kill, not to mention it's lack of a lingering hitbox just makes it an inferior version of Radec's/Good Cole's level 2, and his level 3 is just not worth the price.
His moveset isn't bad, but he doesn't really build much AP, and it feels like the creators couldn't decide if they wanted him to be a keepaway or a combo character then made him a half assed version of both.
As of right now I have never seen Spike do an AP burst in a real match, and I do play against Spike pretty often. His boomerang, while good, is an inferior version of Dan's axe.
His walls of bananas are effective, but the aerial banana, which gives the most stage control, doesn't hit confirm into anything unless set up ahead of time, and the grounded banana is pretty impractical in a real match, On top of that, it's not super difficult to clear out bananas and due to his inability to actually do anything off of them and the low AP they give, there's no real harm to just walking through them.
The car tends to also be impractical in most situations due to how long it keeps you open,
His bee cannon is good, but it's hard to confirm it into anything and if spaced in such a way as to make it safe, you can't follow it up.
His teleport isn't horrendous, but unlike Sly's, you can be hit out of it fairly easily since your hitbox lingers even after the animation starts, so it's not very good for evading attacks. Since left-right mixups don't do much in this game, it makes the move somewhat useless outside of a few situational setups.
On the plus side, the move where he jumps up and hits with spinning swords is probably one of the best wake-up options in the game. Unfortunately that's not enough to make up for all of his flaws and shortcomings.