My experience is that Americans usually want to portray themselves as fast and ready to do the deal based on a handshake (I think many times based on their simplistic view of the US = the world while we Europeans makes the picture more complex worrying about different environments/laws/regulations/competitors in different countries). However, then enter the American lawyers that usually want to negotiate every little detail delaying everything. I do think Americans are more innovative in the financial markets and in some cases settle for good enough to get a deal done but in some areas they are less advanced e.g. M&A insurance is more used in Europe. Not sure who has the better deal culture though…
