Can I share another video? I sure Ken!
(Yes I know that was a terrible joke)
Ken is the undisputed combo king and best character in the game. I'm not exaggerating: if you know how to use him, he's literally the best. There's nothing he can't do, and there's similarly nothing enemies can do once he has them airborne.
Hadouken (idle + special) is what you think it is, no different than Ryu's. Ken's Tatsumaki Senpuukyaku (walk/run + special) hits up to 4 times, and juggles enemies low. You can chain normals, supers, and other specials right after it with ease. His Shoryuken (down + special, or special during normal combo) hits 3 times. If you want to know the difference between his and Ryu's shoryu--Ryu's does most damage at the start of the jump, whereas Ken's requires all 3 hits to land to do similar damage.
His supers are nothing to scoff. Shoryu Reppa (down + super with 50% meter, or mash attack with 50% meter) lands 6-7 hits and travels a good distance. Shippu Jinraikyaku (super with 100% meter) lands 9 hits, and easily combos into anything. Not to mention, it's very fun to watch.
Ryu and Ken have obvious similarities, but their differences aren't just in the mechanics of their specials. To balance the game, all of Ryu's attacks do a little more damage than Ken's. But while Ken is numerically weaker, his juggling capability more than makes up for it.