Hey there dr_devil, if you look at the list of the CA-approved schools, scroll down to the Poland, Hungary and Czech Republic sections and you will clearly see that they mention that the 6 year english programs are also recognized. Unfortunately there are no other European schools that are CA recognized other than few ones in these 3 countries.

The reason why many people use CA-approval as a standard is because it is like a rating in itself. Getting a CA-approval is both hard and time-consuming (and not to mention the tons of paper work needed to get the approval!!!). If the respective medical school is not CA approved, that just means you won't be able to practice in California. You might then have to check with the other state medical boards if they recognize that particular school.

The advantage of being CA-approved is that, the students from that school are entitled to work in any 50 states of the States (US).