I use them for XTOL (2 2L + a regular 1L bottle) and haven't had a problem yet, although I just finished my first batch of XTOL (just over 6 months)...don't know if it takes more time for these bottles to degrade?
I haven't found the cleaning too difficult, I just fill with soapy water, shake vigorously, dump and repeat until there are no more bubbles.
Oh, and I bought mine at Adorama.
How much can you compress the 1-liter bottle for? In other words, how much liquid fits into a compressed 1-liter bottle? In my case, it was still 60 or 70%. I do not see the point.