What benefit is there in using cl.HK? I saw Daigo using that in the past and I see laugh use it sometimes. I saw it vs Viper and someone else. Dont remember.
Considering old videos of Daigo playing Ryu, there are some reasons to why he (or other Ryu players) tend to use close standing round house in general.
After studying just about every Ryu player in Vanilla, I've noticed the usage of standing round house as a way to catch back dashes. If they back dash you get the last hit of cl.HK. If the opponent loves to focus tech on wake up all hits of cl.HK will hit the opponent.
For those of you who don't know what focus teching is: Pressing focus attack and throw while back dashing. If you absorb an attack you back dash safely. However, if they attempt to throw you are still able to tech. It's also a great way to beat option-select back dash punishes (for example jab option select jab + sweep).
In SSF4 AE (as well as AE v.2012), cl.HK is relatively safe on block (-1 on block) and a great normal to frame trap with. Here are some examples of its usages on C. Viper courtesy of Vesper Arcade:
(Be sure to check out http://www.youtube.com/VersperArcade if you enjoyed this video.)
Some other examples of using cl.HK are to beat wake up options or special moves in general. Let's use C.Viper as an example. You can beat almost all her wake up options with cl.HK (except for wake up thunder knuckle and ultra). If your cl.HK connects you can actually follow up with some of the combos in the video above.
Another example is Daigo against Vega (Claw) players. I don't see him doing this as much anymore, but he'd use cl.HK to remove the claw or mask on Vega players. Interestingly enough, it eventually worked but it's not as practical given there are better options on offense when Vega is knocked down.
In situations where you become predictable in using cl.HK, your opponent can counter and just throw you out of the move (given the move has an 8 frame start up). Other times, the opponent can just wake up ultra you. So be careful on how you use it.
The final use of cl.HK that I'm going to bring up is the hit box. I'm not exactly sure if this was in Vanilla, but when you hit someone with cl.HK and FADC towards your opponent you can actually pass through their hit box and end up on the other side like so:
(Video courtesy of arjan127 - You can check out his channel at youtube.com/arjan127)
What do you guys think of the usages? Leave your questions and comments below! :)
P.S. One thing I forgot to mention, there are times where Daigo (including myself and other Ryu players) have accidentally pressed cl.HK. We just messed up our kara-throw (heavy kick is Ryu's kara cancel for extra range on his throw). :)