There's no right or wrong answer for intervals that's going to suit everybody, that's for sure.
I'm in the camp of needing the longer walk break for my lungs and breathing more than anything, and I really need that longer (1 minute) walk break. I'll just keep trying to lengthen the run time and keep my walk the same. As long as I have that moment to keep my breathing in check (exercise induced asthma) I'm pretty sure I can handle anything a half can throw at me. Well, to a point. I'm pretty sure I'm going to die while running Tink in a few weeks.
In other news, I need to stop buying things!! I'm a big fan of Old Navy's activewear capris and they are on sale right now, so of course I ordered a whole bunch of fun prints. I've decided I just want to be super colorful when I'm out running or hiking. Ooops. But I'm still cited for them to get here.