@Darth:
there are too many cliffhangers and suprises, to the point it stops being entertaining and starts being almost annoying.
Nah, this has basically always happened. It's always like WOAHHH every few chapters, but a lot of them come to nothing. Which is maybe a little tiresome weekly, but it reads fine in the volumes. I don't think this element is actually a particularly new thing.
primary example here being Burgess and Diamante, both hyped characters that were reduced almost to a joke.
You sure about this? They did alright in there little bit of paneltime, and Diamante definitely has more to come. I think it's really far too early to say this; unlike B and C blocks, D block wasn't really used to show off characters and fighting and so on, so it's actually something I'm pretty happy was mostly off-panel? And who knows what will come. Kyros vs Diamante in a sort of Riku era Colosseum unbeatable vs Donquixote era Colosseum unbeatable face-off? Burgess just doing something crazy and unpredictable like driving gigaPica headfirst to the ground? Until we see what comes of it, you surely can't criticise D block of all things. Surely Usopp vs Trebol & Sugar should be your first example? Then Franky vs the world? And the Sunny Team vs Jora after that.
For example, I do not feel any sort of exciment for the upcoming Doflamingo vs Luffy fight, because it was not build up, and personal stakes of Luffy in the whole conflict are rather insignificante.
I know what you mean, and I definitely felt like this early in the arc. It was all "Law's plan to take out Kaido." There was no investment in Doflamingo's defeat, and it felt like they were looking straight over his head the whole time. But I felt that Law's backstory has nodded towards some kind of reason there … which we'll get in full eventually. More importantly, there's what Luffy said in the chapter before this one. He's seen those little bits of the darkness of Dressrosa - Rebecca and the prisoner gladiators, Kyros to some extent - and they clearly gave him motivation to take out Doflamingo. As he said to Law, the consequences can be dealt with when they come - beating Doflamingo is priority #1, not just because of some plan or because he's directly antagonising them, but actually because of the things he's done to Dressrosa.
Franky kind of voiced something similar way earlier on, but it wasn't really capitalised on. Hopefully it will be from here on out.