I just played a game with those first 10 cards you guys posted, and it was... interesting. Most noticeably, 5 out of the first ten of your favourite cards were treasures.
Kingdom: Credit, Dwarf, Hunter, Philantropist, Heirloom, Griffin, Crystal Ball, Harbinger, Deed, Mill.
I am a mediocre player, but here's what my experiences were:
Philantropist and Dwarf made an interesting team, as Dwarf draws the Gold Philantropist puts on the bottom of the deck.
Heirloom was very strong, and opening with it turned out a good move. It didn't actually make Credit less interesting, but i must admit that all those Treasures were a bit confusing first, so probably i didn't use both cards at their full power.
Credit became a little of an liability later on, especially in a game with so many treasures - but other players Philantropists made up a bit for that.
Mill was worth 6 at the end of the game, and everybody bought exactly 2 (3 player game). I liked how you want to stop buying them on your own, because you knew that would actually make you have less points.
Griffin made it possible to do several turns where you buy Duchy/Estate, and the combo doesn't break that easily. One Griffin usually was enough to earn a lot of points.
I can't say anything bad about Hunter, it worked nicely as a filterer. It also was good at triggering Crystal Ball. I didn't get the chance to play that one very often, but when i did it was obvious that 5$ is not too much for it.
Harbinger was also quite strong, but that too might have to do with Philantropists Gold-giving. Almost always i would turn up such a Gold and have to choose between 2 Coppers/Action card and Gold.
Deed might be a bit too strong, but i can't say all too much, as i didn't play it excessively. With only another Silver in hand i guess it was better than a Gold, and it also worked nicely with Griffin.
If anybody wanted a playtest for his favourite, here you go