The Wells Fargo student loans for parents seem to be more flexible than federal loans.
With the Prime Rate so low now (and it doesn't look like it will be going up soon) it seems like a better deal than Direct PLUS loans. I like how the money doesn't go directly to the school- so you don't have to wait for them to refund your balance (at which time it is too late to buy books before classes start).
Paying the interest while the student is in school, seems like one way to make it more safe. You pay the variable interest now while its low, instead of waiting until it all becomes part of the principal later on at a higher rate. The federal rate is high- 7.9% for everyone regardless of credit rating! Why would anyone with a great credit rating go for that?
The graduation discount seems more like a gimmick than any sort of a real benefit. Who goes to college with the thought that they might wind up without a degree- and who in their right mind would borrow, thinking that? But things happen, and you never know. It's not anything you can count on, really.
All in all, I think the parent loan is a better option for filling a tuition gap, and I imagine that's what Wells Fargo prefers too.