If you read your handbooks, though, you'd find a whole slew of errors and typoes. I noticed a lot of them in my three core books.
So, they took the time to revise the books that they had originally rushed out the door. But, since saying "we rushed that first volume...you better buy these revised ones" would be too much of business suicide, they put in a few tweaks here and there (you know, because in rushing through the editing department, they also didn't playtest their own rules). Now they try to pass it off as a v 3.5 just to get you to buy all the books.
Sorry, I'm sticking with my v3.0 ones and not buying anymore.
And that playtest thing is true. They didn't do anything real tough to test the limits of abuse that would be possible. What did they spend a lot of their time doing? They all made a bunch of Halfling Barbarians and acted all retarded about it. They actually posted this stuff on their RPG part of the website like it was something cool.