Asmo - another great post from Da Man...
To clarify - this is Chu Ka tong long, not Chu Ka (Jow Gar) as in "Hung Tao Choy Mei"... Interesting how that punch is virtually identical to what's done in Fukkien white crane and somewhat similar to wing chun.
Personally, I am not a big fan of pheonix-eye punches to solar plexus, or of wristing up (wing chun) or down (chu ka, white crane) at the end of a dik choy. IMO phoenix-eye is good for softer targets like eyes, throat, but if you go for solar plexus I prefer a more solid punch, ie yut jee choy.
Same thing for wristing punches up or down - I do a alot of heavy bag work, no gloves. Hitting something heavy and hard while wristing up or down is generally a good way to get hurt

, so I prefer a straight wrist.