I did a taste test of the Kiyomi, Dekopon/Sumo, and Thong Dee to compare the Thong Dee fruit.
Here's my taste test results:
1. Sumo, best taste-sweet with slight acid
2. Thong Dee, good-not as sweet as sumo, but very good taste with no acid/tartness. Typical pomelo firmness and flavor. Tastes better than Chandler, Mato Buntan, Reinking, Chironja, Tahitian.
3. Kiyomi, juicy and mildly sweet (7 out of 10), least flavorful of these
Some photos below. First 4 people to request seeds will get them (around 10 each).