According to the Tower catalog, the SX was a "special purposes" (hotrod) engine, with pretty high rpm range, and ABC. The ABC is good, but the rest isn't, for stunt. They were used by some in 80mph combat, but at $125 each, that was thought to be a bit steep for what many consider a 'fun' event. It appears like OS has dropped the SX and come out with the new AX, in ABL cylinder configuration, whatever that may be. I don't understand why they wouldn't keep the same design and adopt new cylinder technology (if it's better) to it. Unless that technology isn't as good as ABC, of course.
Short answer is: Probably not for your purposes, unless you want a go-fast combat-ish model for reflex tuning on occasion.
Steve