I just found your build and got caught up! Welcome! LOVE the coping and deck!!! The glass tile and the stone are beautiful together! BUT, since you asked...I agree with your wife. The glass tile is PERFECT on the spa. It stands out as a focal point and is lovely! As the waterline tile against the stone, I think a larger 6x6 tile in a coordinating color would go better. Is it too late to change it??