I purchased two cases of series 1 and 2 cases + 3 packs of encore edition.
There was a lot more of encore edition made and some real whozits in it but also some real "home runs"! (i think there were 499 cases made of encore and only 199 of the first edition)
Personally if you can get series 1, Id go for it! BUT... if you are buying a case expect a duplicate within its contents both cases I bought each contained at least 1 dupe! (there are a lot of herbert Hoover cuts in there too!)
Both were exceptionally neat products to bust and it is really addicting! You never know what the next pack will yield! You will get a lot of Check stubs that is a given! In series 2 you will also get an auto of a sports star that quite possibly came from a UDA authenticated item (I got a Peyton manning signed football) There are also a ton of Pete Rose autos in series 2!
The checklist for each release is on razors site. A word of caution though... Masterpieces (1/1's) also have regular issued cuts that look no different than the 1/1s except the 1/1 notation on the case and the framed part of the card indicates Masterpiece edition! They really dont carry any weight of value on ebay!