Some salient questions for picking a program are Which program is the most conducive to the production of my best work? and Which program will maximize my prospects for post-graduation success?
Prestige might be relevant to the latter, but you should distinguish art-world prestige from overall prestige, to which your post addresses. Besides, ranking methodologies become more suspect as the purported subject they're ranking becomes wider in scope; ranking an institution "overall" is much harder than ranking an institution's art program.
So it seems the QS rankings should play no role in your decision making. Consulting your teachers would be a start. Good luck!