Is cracking WPA/TKIP faster than WPA2/AES?

Hi.

I was wondering whether brute force cracking of TKIP is faster than cracking AES. I have a few networks here that use WPA/TKIP and I'm wondering whether it makes any sense to switch them to WPA2/AES.
Is it worth it? Will it make cracking more difficult?
I'm asking about oclHashcat specifically, since it seems to be the only one that can use GPU to crack WPA and WPA2.

Thanks.