(Update: PuzzleDonkey is no more, in this incarnation, but it has now moved to facebook. - Murk) The Donkey, i.e. PuzzleDonkey and I are parting company rather earlier than we did with PuzzleDonkey 3.
There are some nice puzzles in there, but rather too many wordy type ones for my taste. I liked 1.03, 1.13 (despite being stuck there), 1.16 and 2.03 the most.
The sheer density of the 'wordy' ones was just annoying me, and 2.04 was the final straw. I just had no interest in going further. A pity, as some of the later puzzles in PD3 were really good, and its a shame to miss them. My favourite PD3 was the barcode question.
PD3, by comparison, was much more varied - so getting past a wordy one had the incentive that the next one would stand a good chance of being of a style I liked. This incentive doesn't exist in PD4, though I did appreciate certain features like the 'colour blind option' (though not colour blind, it was sometimes useful).