I have been wondering this myself lately ....
Although I want a good ab region, I dont want it too BIG, especially side-to-side...
I have been on for like almost 5 weeks now, training abs in additon to everything else. Although I have eaten fairly clean and therefore have kept water retention down, and fat incseases have been ZERO (think I have actually lost some) I have notiuced that my waist is LARGER.
So, I am debating this myself.
I am being careful to NOT work obliques directly, ony really work the center-abs, so as to not mke thinsg wider.
BTW - I am NOT one of these guy that just wants to be BIG. I want a good, symmetrical look ..... like Zane.