If you love Deadpool 1, you WILL be disappointed! But otherwise . Good movie on its own
Unless you are a fanboy(i mean this without being rude). its ok if you personally love it. But yes it is not as funny as Deadpool 1, full stop.

Deadpool 1 had a simple plot a simple storyline, simple budget. And so they killed it in writing, the jokes 4th wall breaks were off the chart. It was character driven story.

Deadpool 2 is a plot driven story. and the plot is just weak. The plot center is this kid Russell who is not well written and turns out to be annoying and not worth it honestly. But to each his own I guess.

Deadpool himself kills it and tries to carry it throughout. If you can love the movie solely on that. You will enjoy it.

Lot of jokes may not pander to international audience easily. I had hard time understanding few lines. But I can imagine they are funny. Will see it again with references

Cable was good, but underused in my opinion. I was expecting him to blow Deadpool's mind and imagining them to be each other's throat throughout the film.

[spoiler] That does not happen. The plot shifts. Cable joins deadpool. actually saves him in the end. while the villain is juggernaut. xmen 3 last stand memories anyone?? [/spoiler]

I saw DP1 again recently before seeing DP2 and I was laughing out loud at most stuff and the movie kept me hooked. DP2 does not do that. There are scenes in which I was waiting for things to move along.

It also suffers from the "trailer" effect. You know where you have seen most jokes and cool stuff in the trailer itself. And then in the movie you expect more but end up with nothing.

One awesome joke I found in trailer was Deadpool saying to Domino that YESS XFORCE IS DERIVATIVE!! . They cut it for some reason. [spoiler]He simply ignores her and says NO ONE ASKED FOR UR OPININON PETER[/spoiler]. I mean why??

Some humor felt forced dare i say. I mean too much MCU and DC remarks.

but some humor really kicked ass.

In short I may not want to see it again on theaters. Deadpool 1 I could have seen it over and over agian.

Many people may disagree. I write this objectively.

Good Luck.

UPDATE:
went for it the second time. (because i had time to kill and i was nearby).
i do not want to redact anything. i stick by my comments and score. "you can enjoy this. but not as good as dp1"
there are lot of referential humour instead of contextual ones so some jokes will be hard to understand as i said before.