As scentemental notes above, we've been talking about 1stperfume.com for years! I remember posting a warning a LONG time ago. Anyway, the short answer for this place is that you are ALWAYS taking a risk with them. Simple as that. I ordered from them a few times; the first few times were okay, the last time (almost two years ago) was an absurd disaster.
Why do people keep ordering from them? Well, two reasons that I can see (or, these were the reasons I bought from them)... sometimes they are the only place that appears to have something and SOMETIMES their prices are cheap. The first time I ordered I was looking for Knize Ten and they had a bottle for less than $30. That was a steal and it came quickly and easily. This happened again, IIRC (it's been a while!) on some Helmut lang stuff.
BUT, then I got greedy (haha) and decided to order from them again on some Costume National and a few others. DISASTER. Not only were the bottles incorrect in the shipment, they shorted me a few bottles, mischarged me, and then were slow as molasses refunding, contacting me, etc. and when they did contact me, it was really like they had no idea how to speak English or read it (I told them "I'm missing two bottles," they replied, "Please ship the bottles back to us for refund.")
So, because they still appear to have hard-to-find bottles, sometimes very cheaply, we'll still have threads with angry buyers.
SHORT STORY: If you want a guarantee of ANYTHING (from customer service to the actual bottles), NEVER buy from them. If you want to take a chance on a bottle that seems "too good to be true," you might consider it worth the risk.
Fresh, authentic Knize Ten for less than $30? It's LONG since gone on that site, but it was worth the risk. The second time, though was NOT.
So, I don't buy from them anymore, wouldn't recommend it ever for anybody else, and just shrug my shoulders and whisper "I told you so" when people complain about the bad service even after being warned.