hi shern
Lay flat is better, coz thin and can save space, tip taught by a gf, but make sure when u lay flat, zipper is tight, in case leak...Both boots n blueegg can store 250ml per bag (recommended) but I kiasee,scared of leakage, only store abt 225-235ml... so far so good, both bags no leakage..I have already thawed several blue egg to use when i was in bkk, no complains from my mum so guess blue egg is ok....