I don't see an issue with buying it blindly. Sideshow's return policy is very good.
Nuri, the paint on the nose tip on my replacement was scratched off, they basically told me if we send u another one it would probably get scratched again to as they blame the damage on shipping, not the fact that most likely didn't check it to begin with. So while I agree with you that their return policy is very good, their QC department on the other hand isn't, just look at the replacement problems Orko's revenge has, I can't believe they sent him an even worse cape than the first with more wires sticking out!
They either don't check their replacements they send out or because most replacement parts are bad, they can't find any good ones to send out. Thus, they send them out the bad ones anyway.
I remember when I received my Alien Big Chap LSB, I thought it was terrible. Not just the faults, but the overall bust in general was just rubbish. I sent them an email and told them I wasn't interested in a replacement or credit, just wanted my money back. They simply got me to destroy it and promptly refunded my money.
The fact that they refunded your money just because you didn't like your Alien piece, not just because it has faults, was unbelievably nice of them and in that regard, I would say their return policy is the best. However, in my case the difference between this statue and your Alien one is that if I got a good one free of QC problems, I wouldn't want to destroy it or get a refund as IMO it is quite an impressive piece. Whereas, according to you the Alien Big chap LSB is just a horrible collectable, which is why you wanted a refund right?
The problem is that it is hard to get a good one of these, so IMO it is best to check this out first. That being said, I am sure there are many people out there who have gotten a good one from Sideshow, but I don't think it is worth the risk to buy it blindly no matter how unlikely it is that you will get a bad one.