It is, all of it, very, very good.
To be fair and honest, I've read them and not played/dm'ed them.
However, I'm usually pretty spot on for dming and reading and my assessments for what my players will like and won't has been good so far.
I have the first two adventures and "the bloody fix" which is by 0one, but not part of the adventure path.
I'm planning to buy (this month, and sight unseen, but based upon the quality of what I've seen so far) the Great City setting and the rest of the AP stuff.
It's not just "the best of what is out there for 3e right now". It's among the best I've seen for 3e ever, and I'm a rabid fan.
I'd put it/them up there with the Necromancer Games adventures (some of my favorites) as well as a few gems from Monkeygod and Hogshead.
To give an even clearer picture, I've been buying 3e stuff for the past year, plus (since 4e was announced and 3e stuff got cheap). The only products I've been truly excited about are these, Wolfgang Baur's Open Design Products, the War of the Burning Sky Compilation, Razor Coast (date of release to be determined), and the latest Pathfinder AP. Everything else has been good enough to buy, but not scintillating in my opinion.
My advice: buy a pdf of one of them to figure out if it is something you like. If so, buy the rest.
A warning: some of the very earliest materials are not the most well edited in terms of grammar, as the editor (?) is italian and translated from english to italian to english again...resulting in some peculiar grammar in a few places. This is irritating only to english majors and editors, and I find it excusable now that I know why it is so. This is not the case for later products (like the adventure path).
I hope you check it out and enjoy it as much as I (clearly) do!