The future arc was okay when it started, but it's turned to shit pretty fast. The boxes on the whole are a retarded plot device, surely the rings could have a better use than that. Plus the pacing's been totally thrown off, it's like the whole arc itself is going at a snail's pace. (Tsuna has been trying to perfect the X-Burner for how long now?)
Flashbacks and other timesinks that have no real impact on the story. Then to top it off, Deus Ex Machina at every corner. 'Gamma verus Hayato THIS IS MY FINAL ATTACK, REALLY!', Yamamoto getting training from beyond the grave, Hibari turning up out of fucking nowhere, Reborn's re-appearance and now this.
And whatever happened to Ginger Bread?