I couldn't decide, they will have their similarities & yet be different. I love Lady Is. & I love MK's & both seem to be good parents. I guess it depends on if you like a stronger roth influence then Shin-Yi's Pride would be 50% roth, (25% sand, 25% phili). Booth's Sand Lady would be 50% sand, (25%stonei, 25% roth).
Good Luck deciding!
Another thought ......
so how much money would you save buying one?