Okay, just went to the check vendor's web site and ordered my standard blue checks i.e. the cheapest ones available. Only $15, but I got an $11.50 discount for reasons undisclosed then the little darlings charged me $8.00 to mail them in a way so I would receive them in 11 - 14 days. (Priority mail with 2 day service would have cost them $6.45.)

One of my alternatives was a "Personal High Security" check with a nifty "Holographic Security Stamp" that would help buyers to "protect yourself against check fraud." ($26.75 for two boxes) But I'm thinking, how would that work? Wouldn't getting the checks with the Disney characters afford me the same level of protection?

From your bank's perspective, if a customer invests in these checks and your bank pays an old check or a fraudulently cloned (hologram free) version of the new check, who do you think your customer will blame? Clearly, the latter would be a forgery anyway. However, the "old" check with the same MICR line, but no hologram would still be properly payable. Yet, your customer is still going to insist you were careless because you paid an item that wasn't a "high security" check.

How is this "high security" check anything other than a consumer scam in its own right?

I have seen that sort of option also and all I could think of was UDAAP.

Many banks have no idea what their check vendors are peddling to their customers.