Just returned from 3 weeks in Germany & Italy. Temporarily reactivated my BB 9650 Bold for the trip since my VZ iPhone 4 is CDMA-only. We needed to have a US # primarily for emergency contacts, but were willing to pay VZ's exorbitant global rates for calls & texts. I updated the OS & apps and checked on the SIM card with VZ before leaving to be sure that all would work properly, which they said was the case.
The phone seemed to work in Germany (on vodaphone.de) but we had real problems in Italy, for which I called VZ's global support team several times. They couldn't really help much in the end. We had to manually adjust network settings so that it would include 2G & 3G networks. Even so, we apparently never received a lot of calls or texts that people sent us. Also, I noticed that the phone alternated between Vodaphone.it & WIND, depending on location; that's probably normal & shouldn't be a problem, but I wonder if it affected our ability to receive calls/texts. Ultimately, I could only get the BB to work if I pulled the battery & rebooted it -- not very convenient or useful. Oddly enough, the global data seemed to work fine at all times although we hardly used it. Could be the phone just wasn't adequate but I have to question why it only worked some of the time and not others. Will take it up with VZ global "services" in a day or two after my jet lag wears off!
Ultimately, my advice would be to buy a local phone (in Switzerland or Germany) for greater reliability & much lower costs (even for data). Even if you have to buy another SIM card when going to the next country it will probably be cheaper than using VZ's global "services" if you have to make/send more than a few calls or texts per day.