I've made 2 Booga Bags and have been really disappointed with the size both times. I'm a really tight knitter, so I suppose that's most of the problem.
I'm currently making my 3rd one (with Noro Kureyon, of course) and have altered the way I'm doing it. I cast on 50 stitches and worked 50 rows in garter stitch using size 11 circ's instead of the 10.5's they recommend. Then I picked up 25 stitches down each side of the rectangle and another 50 on the other long side for a grand total of 150 stitches. I just started working in the round last night, and I've got 8 rows done. From what I can tell, 10 rows will be approx 2 inches, so I'd like to do 100 rows and then go from there. So far, I'm really pleased. The bag is going to be plenty big, without being absolutely huge and impossible to finish.
I'll let you know more as I go.