In blackjack, 2 shoes is nothing. It takes thousands of hands/hundreds of hours to get to the "long run", to where you have a high probability to be winning since the edge with card counting is so small. To give you an idea of what I`m talking about, 94% of the time you`ll be winning after 500 hours of play (on 6 deck shoes). As far as what count systems get to that "long run" more quickly, those will be the count systems that are multi-level (explained in the article below if you don`t know what that means). I can`t speak for everyone, but I think the last thing most people want to do on here or talk about is the debate about what count system you should use or is best, etc. That horse has been beaten to death in blackjack forums imo. Most on here would probably tell you to pick one of the more simple count systems when starting out. Then if you want to go to one of the stronger ones later on, you can always do so. After all, keep in mind that there are plenty of blackjack professionals that use the simpler count systems like hi-lo, etc. There`s a good article about different count systems below; it`ll give you a better idea of the reasons why I say what I did about that. Mainly it has to do with the fact that more complex counts take a lot longer to perfect (meaning that your error rate will probably be higher also, at least in the beginning), and for all that work you put in, the difference in how the counts match up to each other performance-wise is not that big.
http://www.blackjackforumonline.com/content/hundred.htm