So there's no question that these cards are full of perks. But you need to evaluate each card on it's own merits because they're provided by many different card issuers.
There's also wide variety in the rewards you can get with Visa Signature credit cards. For example with certain cards you earn rewards on purchases that can be turned into a deposit and placed in an account, or you can earn bonus cash back in categories that change or earn travel rewards and get travel perks.
As you can see, there's a variety of choices when it comes to Visa Signature cards. The best approach is to decide which type of rewards you're interested in first and you'll narrow your search considerably.