one step ahead expandable diaper bag

[twizzli]

I've read the reviews posted here but was wondering if this bag is heavy this bag unpacked. I'm looking for something similar to the mothership type bags in terms of size, but for much less $$!!

http://www.onestepahead.com/product/27211/123757/117.html

[twizzli]

also, do the side pockets fit avent bottles and sippy cups or just traditional narrow bottles...can't tell from the photos.
Please post pics if you could!!!