TAD KT88STR vs Gold Lion KT88

For the past two years I've been using a quad of the Gold Lion KT88 in my PrimaLuna Prologue Two. It's about time to replace them, and I'm torn between getting another quad of GL's, or trying something new with the TAD KT88STR. I've been unable to find a whole lot of reviews on these on the Internet. I emailed a guy from an online vendor who told me the TADs are made by Shugang for TAD in Germany. He said he had not used them in his own amps, but says that all customers are happy with them, and that they are similar to the GL's but with a bit more "bass authority". One man's "bass authority" could be be another man's "bloated bass", so I'm not sure how to take that comment. To me, bass authority would be more impact, extension, and control.

Has anyone heard the TADs, or better yet, both the TADs and the GL's, and can offer some comments/comparisons?