nagi2k4
Only major downside I've run into is that there do not seem to be any native terminals for Windows that even come close to rivaling iTerm 2. Cmdr is decent, but has some weirdness around colors and ligatures; Hyper is also decent, but has some rough edges. Suspect that'll change as more devs start needing decent *nix environments to develop on.
The end result of that will be that the global financial system is going to be bifurcated into "compliant" and "non-compliant" institutions. Believe me, most banks/insurance companies/financial entities will find it worth their while to eventually become compliant.
The reason that more countries aren't complaining about this (and most are actually entering into bilateral enforcement agreements with the U.S. Treasury department) is that they'll then be able to get access to the same sorts of information on their own citizens that the U.S. is getting on their own as a result of FATCA.