You have bought already? Or planning? If you haven't purchased yet, have a look at this.....
http://b2b.guay2.com/eng_news/10shotshow/10shotshow.htm
go down to the new releases and you will see a 552 that is going to be released very soon. I would suggest getting age verified, if you are 18+, and then when these release, have a retailer bring one in for you.
I have a G&G SIG 550, and the quality of the gun is outstanding. Full metal. Solid, heavy, and the quality of reproduction is the best. ( I also have a real steel Swiss Arms Black Special to compare against.
Believe me the G&G SIG 552 will be worth waiting a month or so for. And way worth it, rather than getting a plastic body 552.