Trent's comments about the sizzle are spot on...this backbore really sparkles, but it is not so bright as to be annoying...there's still a real good core to the sound. The TA-Z top doesn't work for me, so I will be experimenting with other sizes.
I loved the A2 because of the great core sound it gave me. The KA1 takes my me to another level. The sound is crisp yet full with sparkle. Incredible! Oh and it gave me two more notes to my playable range just to show off it is the complete package. You have to try it!