Only difference in his work then & the past few years is that he's toned down on his high spots. His matches in 02 were just as good as his matches are now, now his character is another storyI don't think so...
AJ has improved significantly in the ring over the past several years. Even by his own admission he's a better worker now than he was earlier in his career. Daniel Bryan has always been a wrestling savant when it came to ring work, while AJ had potential but it took him time to really learn the value of selling and mastering ring psychology.
AJ started to evolve and become a better worker through his matches with Joe, Angle, and Sting. There's a clear difference in his in ring style and psychology before and after he worked with those guys I mentioned. AJ then took his work to another level after he left TNA and started working in Japan.