Bought fake pro duo cards- am I screwed?

UGH!
I just bought 8 4gb Pro Duo cards from a website called www.superdealsco.com

After checking them out I see they're quite notorious for selling defective or fake crap. Shit.

http://reviews.ebay.com/FAKE-Sony-Me...00000001236041
FAKE Sony have easily identifiable FALSE Sony part numbers with extra letter T and also mixed/incorrect UPC Part Number on the retail paper insert.
PRO Duo:

4GB (MSX-M4GST/X), ?-??????-??????.

That's me. That's the cards I got.

So here's what I want to know...is anyone actually using these cards? How bad are we talking? Are games playable? What's the maximum amount of room that is on the card? I got them for a good price so I'm not too terribly worried about it but I'm wondering if I get the chance to return them should I or just say to hell with it and use them.

depends i guess..i've ordered a fake 4gb "sony" pro duo on ebay and it indeed holds almost 4gb... putting the stuff onto the card though, takes longer than a legit sony/sandisk mem stick.

as for how long? its not killer.. but annoying haha

but some fake mem cards are known to hold only up to HALF of what the advertised capacity is and all write speeds for fakes are very slow

Well I mean I'm going to be playing homebrew on them...its not a big concern. But if it's going to have only 2gb on there that's a definite deal breaker. This stuff pisses me off...Sony should just stop playing around and give us a cheap $50 100gb card and answer my dreams! ;)

I bought a Memory Stick off eBay - probably fake, but it holds 4GB and works fine - hope your experience is similar.

Cloudy

EDIT: It is fake, checked on that guide. Still works dandy here though :)