Though I'm only in Platinum. I've come across a few decks. Quite well balanced. Since I'm not too familiar with them, they've caught me off guard. But if played right, they can be quite fun it looks like. Would love to build a deck with them, but using my gems other ways right now to build some other decks.
Agreed with the OP. If you know about the actual Legendary Six Samurai monsters and the Support cards such as Secret Skill of the Samurai, you would know the current Six Samurai is but a figment of its true power. Konami is only giving us normal Six Samurai monsters while the Legendary ones surpass them in everyway.
My wife: got 3 UR Sien from 90 packs total.
Me: still 0 UR Sien after opening 50 packs without reset.