hi! i have read along this post/thread.
i think most replies were intended to be helpful, not mean. it's hard to write sometimes - facial expressions change the way the spoken word is interpreted.
anyways, i just did a quick search on google and from what i'm seeing/reading, goretex is very similar to PUL. (pul - ready to buy stuff - not the DIY kind - is a soft polyester fabric with 1mil or 2mil laminate on the back). Shoot, I think I have some of that drapery fabric - TOTALLY NOT the same thing AT ALL! Diaper PUL is pretty soft fabric and is breathable, too - like your goretex.) sews up well using a ball point needle.
If you're in the USA, I would be happy to send you a diaper cut of PUL - so you could use it and see the difference between that and a shower curtain. The PUL I use is intended to be used in hospital situations - which is how/why it became such a popular diaper fabric - it can be washed/dried at very high temps - and survive well that way.
you don't need to use PUL or a waterproof outer fabric if you don't want to. i make most of my diaper 'stash' for my younger kids out of fitteds and diaper covers. the fitted diapers are made mostly of flannel - because I take advantage of the $1/yard black friday sale at joanns (that's the day after thanksgiving sale).
It is worth it to spend $30 and end up with 3 yards of pul (shipped in that price!) that you can then make 18-24 diapers out of - depending on pattern you use and size of diaper). I recently had to buy some disposable diapers as my washer was broken for a week.
It cost me $25 for one week of diapers for 3 children. - that's the CHEAP diapers! $50 can make you a stash of diapers in each size (small, medium, large). so for $150-$200 you can be set.
The bamboo, hemp, microfiber - those are all wonderful materials but they are more expensive than flannel - esp if you pay $1/yard for flannel.

anyways, email/pm me offlist and I'll send you a diaper cut if you so desire. consider it a FOM (fairly odd mother) gift - if you are really interested in sewing diapers, you really might want to check out dsd - it's where I usually post - that's diaper sewing divas. you'll get a lot of great ideas from moms/grandmoms, etc sewing dipes.
here's a link to dsd:
http://diaperdivas.proboards57.com/index.cgiBettyAnn
mommy to 3 in dipes. . .