basically what it boils down to is do you want a ski that is a little stiffer with normal dimensions (tnk) or do you want a super soft ski that is symetrical (anthem)?  i have the anthems and i really like them.  they're super fun for park, really poppy and smooth.  i skied the tnk a fair amount last year and they're a really fun park ski as well.  they're just a lot stiffer and more deliberate feeling.  not quite as quick as the anthem.  like i said man, it's really just do you want a stiff or a soft park ski?