Well, they could have done worse, at least most of the original cast was kept, the only character who had to be recast was Cassiday and honestly the new one wasn't bad. But yeah, they changed way too much and edited way too much. Especially bad was "Legend of Thunder" and "A Family that Battles Together, stays Together" I love when we see Brock's family again, and they really messed around with that story. Changing pretty much all the dialogue seemed to be changed, they pretty much ignored that Brock's mother was supposed to be dead (in the dub) but worst of all, they skipped over the scene where Brock leaves all his Pokemon except Foretress with him. That was frustrating. Very little of the Japense music (or none) seemed to be retained throughout Chronicles, dialogue was changed all over the place, and they took a lot of liberties with the script (on at least 5 differant occasions, they made referances to the characters owning Pokemon they never owned)
I think it could have been worse, really, pretty much anything in life can, but it was a step down from the main series' dub, which still had some fundamental problems. However, the idea for the show in general I loved, Pokemon doesn't have a lot of recurring characters and I loved seeing them do stories all about them. I actually really hope they make more. What they should do, is make some post-AG ones with Morrison, Tyson, Drew, Harley, maybe Solidad, and May and Max.