I think you can definitely say that 'generally' the players from some countries are way worse than the avg. ones from others. Good example.. France. French players (especially online) are reknowned for bein' HUGE FISH (Grand Poisson <sp?). Italians are generally real bad too.
Easy way to determine this is by (for online anyways) checking the players on the tables in an MTT on Fulltilt. Sure there are more Americans but look at check out their stats. (& the style of play which obv. results in the terrible stats.). Also, try asking a large sample size of the Top Ranked MTT players (online) and see what the response is.
In the micros my experience has been - Russian players in SNG's are often Very Good, Germans are often quite good too, Brazil - meh.. kind of a mix, but mostly I find they're overly aggress to the point of often bein' mindless/spewy aggression, Americans - you get a wide mix, Italians - usually REALLY BAD (rarely have I even seen a winning micro player from Italy... maybe one or two).
How do I know this? I've played some fairly large sample sizes with a program that displays their stats. from every game they've ever played (on the site they're playing on at the time).. {no it's not Sharkscope < that's illegal. I don't use it, don't have it & wouldn't use it (because it's illegal & it costs money, lol).
As far as live play goes... idk. I have no way of being able to give a decent analysis. As far as online cash game goes... again I have no way of knowing as I don't follow it much.
Brad Booth - > "Like a fight... it's not how you start, it's how you finish"