Mylar, supersafe or any other coin holders; what is your experience?

I have collected coins for a few years now (I'm in my late teens and have collected since my 14's) and have used cheap holders for my coins (home made or bought in bulk); now that i have a little more money, i would like to know your experiences with LONG TERM storage coin holders (knowing that log term doesnt mean eternity, but 10 years at least)

I'll share my appreciations in my short life as a collector:

BCW for me, is complete rubbish, altough it says it's PVC free, without doubt it has lots of plasticizers, for the banknote holders, you can see a kind of "rainbow" when you place them against the light, even you can hear them "squeaking" when you manipulate them; "lo barato sale caro" or "the cheap stuff in the end is more expensive" is a sentence I would use to describe this products.

I have read marvelous things about "mylar" products, like SAFLIP, as I have read they are not what they advertise; I'll spend about 300 hundred dollars in some Mylar and supersafe holders for both coins and banknotes; but before I use this money, I want to know you personal experiences.

Thank you

I find Mylar holders are fine and BCW pages are decent.

However BCW double pages open at top and a top row of coins will spill out, if the page is not lifted gingerley.

I have 400 Mylar holders and they do their job well, except they get quite stiff and I have already broken one with a heavy coin.

I don't trust PVC or push in cardboard holders.

Cardboard circle things I don't like as the staples get stuck and you can't handle the coin.