Bulbasaur is different than Tara Jayne, but is bearable. Charmander in some parts sounded OK (in the parts where the voice was louder it sounded more like Michael Haigney), while there were others where it was a cheap imitation. They could've tried harder to mimic the voice, or better yet, pay Michael Haigney for his!
Strangely enough, I feel that when Ash's VA is working with Pokémon Veronica Taylor worked with (the Kanto Pokémon and Johto ones) or doing things like flashbacks to 4Kids episodes, she sounds much better. I thought DP182, when Bayleef, Totodile, Cyndaquil visited Sinnoh was one of her best episodes, along with some of the Sinnoh league (DP185, battling with Noctowl) with those Pokes. Here was similar as well. She sounded pretty good talking to Charmander.
Misty and Brock yelling "Ash" when he was running away from Charizard actually sounded like the old voices, and in some parts Bill Rodgers did fine. Misty was heard so little that I don't even want to compare, though her's was one of the better/less cringe worthy voices in the Mastermind special.