I actually think that Herry is more underareciated than Snuffy. After all, Snuffy is still a major character while herry has hardly been on the show since the format changed (and possibly before that). While Herry seemed to be a main character in the street plots during the years that Frank Oz was frequently unavailible for street scenes and his characters weren't beign performed by other performers in his absence, Herry would be the main blue monster on the street while Cookie Monster and grover would basically be the monsters who appeared in other productions. Herry only had one line (done by another performer) in Follow That Bird, and didn't appear at all in Elmo In grouchland, and he rarely had any major roles in the various Sesame Street specials (the most major he has had in a Sesame Street special was in the 20th anniverary special). he hardly (if ever) appeared in Sesame Street Live, and I am not sure if a herry walk-around was built for Sesame Place.
I like Snuffy, too, but I like Herry better.