My answer is the Platinum T8's, but my opinion is so biased it's not even funny since I just bought the T6's 2 weeks ago and I am a huge supporter for PSB. However, my answer is depending on a few things....

First, what is your room size?

What are you using to drive the speakers?

Are there any other factors to know about? For example, are you able to get a better deal on one versus the other?

These may help. Also, don't rely on the spec sheet alone because on paper the PSB's never come close to just how amazing they are once you hear them!!! We are talking about one of the most clever speaker designers out there!