Hammer Taboo spare works for me. Has the Taboo core and will give you movement when the lanes break down. Changed the ball surface with 3000 Abralon and right up 5 board the ball would walk to the pocket on THS. Shined back up with Ebonite factory finish to have a more universal ball, and have not changed the surface since. Looks good going down the land if you are looking for that. The Taboo spare is plastic but I don't miss that many 10 pins. just saying.
Last time I looked there were still several on EBay, reasonable.
jodyk24