I have put nothing into strength and have been very happy with my guy (39 PR TD's so far this season).
I have put all of my points into Speed, Agility, and Vision. Also loaded up on Return Specialist (and have an AEQ with it, so that helps). Also found an AEQ with Juke, so working on that too.
Next I'm going to try to train up Confidence and probably keep working on Speed, Agility, and Vision at the same time. At some point might like to get my stamina a little higher (33 right now). Am only playing 30-40 plays a game, so stamina isn't a huge deal, but on the games where I have a bunch of returns, there is definitely a noticeable drop-off in the 4Q.
After I get confidence higher, MAYBE I'll start thinking about Strength. Since I'll never be more than the 4th or 5th CB on the depth chart, not sure if I'll ever bother with jumping/catching/tackling. Although, since I also play ST on coverage I might add to tackling at some point, but so far missed tackles haven't seemed to have been an issue.