It works fine.

In the settings menu there is a option for auto (Auto detect CDMA, if no, try GSM), CDMA only or GSM only.

It will work fine since there is NO CDMA is Europe except for a little bits in Ukraine where VZW does have roaming. They also have CDMA roaming in Asia.

If you are purely using a unlocked Droid 2 Global with 3rd party SIM, in the settings menu set it to "GSM/WCDMA/UMTS/HSPA+ ONLY" which will COMPLETELY ignore the CDMA mode of the device and use whatever SIM card is in the device.

Even if you don't it will work in GSM mode since there is NO CDMA1X/EVDO rA in Europe with VZW roaming unless you are in the capital cities of Ukraine (rare, there is GSM there too).