Americans usually are prepared - they know what is their resistance point, what they should demand. They speak clearly and plainly - during the negotiations in the class, all the instructions and proposals from my friends were straight, and there was no hidden message which I could miss. On the other hand, from my experience, Americans are very distributive - they don't focus on cooperation, rather want to win as much as possible for themselves. Naturally, negotiations are not a zero-sum game, and American negotiators know that - but they rather take than give. The good thing is that the opening position is never their final position. That is something I really appreciate, as it gives a lot of space for creativity. Unfortunately, Americans do not care much about relationships. That it really easily seen in the small talk. Two welcoming sentences and raedy to go! I really do not like this impatience. The last thing I complain about is the very popular cultural minimization, which is when one's (in this case American) own cultural norms need to supersede the cultural expectations of others. But there is a good thing at the same time! Americans' personality is super strong and there's not much that can break them.
Don't get me wrong, Americans taught me a lot, your culture is very different, especially in negotiations. That was the best experience I could get, and I appreciate it a lot.