D684CB vs D704CB.

GO!

I've got the 684 and it's great for smaller lures. Larger jerkbaits and top waters are too much for it. 

 

It's an excellent Squarebill rod though. 

If I were choosing a rod to throw both topwater and ripbaits/jerkbaits on it would be a graphite 705cb.  Of the two you mentioned I would still opt for the 704cb.  I strictly like a longer rod though.

The largest of either that I throw will be 1/2oz, is that too much for the 4 power?

 

685 cb I have is nice for Sammy's and jbaits

I've got a 704cb for jerkbaits, specifically vision 110's. I wish I would have went with a fast action rather than a mod/fast. I don't think the mod/fast gives a good enough snap to work a jerkbait in the middle of the summer. I'm going to switch to braid from flouro this year and see if that helps. I throw a jerkbait religiously for smallmouth year round. 

This is a great squarebill rod if I'm every caught fishing for largemouth.