Clyde is pure offense. His high value and 3 Stud bullets make him one of the toughest shooters in the game right now, and his decent 2 influence allow him to take over deeds right from the get go. His cost is high, as is his upkeep, but you get good raw numbers for what you pay.
His Noon ability is what really sets him apart however. At first glance, it just seems to be a way to force Wanted Dudes to accept call outs with Clyde, which while useful isn't that impressive on its own, so its worth breaking this ability down to see what else it can give you.
First, as a Noon ability that doesn't require booting, it can still only be used once per turn barring effects such as Good Stiff Drink. However, as it doesn't require booting, it can be used even while booted. This gives Clyde a once per turn call out that he can use even if he's booted to move somewhere, or been booted by an effect. This makes him very good at pursuing mobile dudes, or dudes that boot to move to an out of town deed. Remember that booted dudes as well as wanted dudes cannot refuse this call out from Clyde, so he is difficult to get away from.
While you can't run, you also can't hide, as Clyde's ability also allows you to call someone out at their home, as it isn't the Call Out Noon Play. Use the Law Dogs Outfit ability to make them wanted first so they cannot refuse, or simply scare them into booting themselves uselessly at home. This can be very useful if you play Clyde in your starting posse, as he can pressure an opponent that wants to rely on high influence to keep them in the game while building up a bit, but can be equally useful against a Sloan Gang deck that builds up a few control points with The Sloane Gang Outfit card or Allie Hensman and then tries to run them off home to hide and protect their Control.
Clyde is one of the few Law Dogs without the Deputy Key word, which might make him seem to not synergise too well with Rafi Hamid's ability, but if you have a Government deed you want to protect, Clyde could boot to move there, and still be able to call out the trespasser with his ability, and then Rafi could send in the back up. There are worse places for Clyde to end up than The Town Hall, as it will offset his high upkeep cost.
Clyde is an extremely strong Law Dog card, and worth considering starting against certain deck types.