Tried my friend's AX99 LCW (4UG5) few days ago, I can say it's significant different from my AX99 old batch (4UG5). The AX99 LCW is more light head and able to swing faster, I felt it's more easy to play overall, smashing feel more effortless compare AX99 old batch, maybe due to my lousy skills, hahaha.
When I switched to use my another AX88D (4UG5), my smashing wasn't powerful as AX99 LCW (4UG5), but swing speed both about the same. That's my personal opinion based on my personal experience with my lousy skills. Now I only use my AX99 old batch for warming up and played for first 2 games, then will switched to AX88D (4UG5) or LDF (4UG5) for the rest of the games.