Needed to move 1000 contacts from my old Exchange server to my new Google business mail server and this did it quickly and efficiently including merging any duplicates, etc. Sure you could just do an export and import from both environments, but for the very reasonable price of $6, I was able to do it effortlessly and I am now covered for any other moves or syncs I need to do in the future. Like I said, highly recommended. :)
Bertzillas about Contact Mover & Account Sync, v2.2.4