The buff provided by Caduceus is a powerful one, which ensures that it is going to see some Commander play
Tunnel Tipster's first ability will trigger as long as a face-down creature entered the battlefield under your control this turn, even if that creature has turned face up or left the battlefield since
Its rarity is amplified by unique distribution methods, making it difficult to pull
Of course, the reality is a bit more muddled when black can kill creatures easier, green can destroy artifacts and enchantments, red can deal with lands, and blue can bounce almost anything for a temporary removal
Its a bit better than that, and it subtly gives some hate to the decks that revolve around interactions with tokens like Treasure tokens, or even Clue tokens