I bought three unlocked smartphones (on Amazon) to use and evaluate:  Samsung Galaxy 4, Nokia 920, and Blackberry 9930.  After six months experience, here are my thoughts.I have relied heavily on my PC and a dumb cell phone for more than 20 years, but I finally decided to get a smartphone.As a user I like the Samsung least in terms of its user interface and focus on advertising stuff.  The Nokia 920 has a brilliant screen and the best graphics for games and movies.  But as a communicator, the BB 9930 is the best!To quote a line from the movie Star Wars regarding the Millennium Falcon, "it''s got it where it counts".  If your focus for a phone is (1) phone calls, (2), SMS, and (3) email, then Blackberry is the best.  Virtually no advertising fluff is imposed on the user.  I have not personally owned the BB Q10 or Z10, but based on my study of published user reviews, it''s clear that the BB 9900/9930 is preferred by many BB users.As I said, I wanted a phone, first and foremost.  However, you might be interested to know that it is also a brilliant MP3 player.Sorry this posting is so long, but I hope some readers find it helpful.P. S.  My service provider is Telna, which I have used for years.  Their pay-as-you-go, no-subscription-contract (for voice, SMS, and data) is brilliantly cost-effective!  Their GSM sim card interfaces perfectly in the Blackberry 9900/9930.P. P. S.  I read the reviews of some users who have encountered SETUP PROBLEMS.  As I said above, I have an unlocked Blackberry 9930, an unlocked Nokia 920 and an unlocked Samsung Galaxy 4, all purchased from Amazon.  Please be aware that all unlocked phones have setup challenges that will be  "learning curve" for the new buyer.  Here is some help for the BB 9930/9900.I believe most of my comments below would apply to 9900, but please be aware that the 9900 does not support CDMA; the 9930 is both GSM and CDMA capable.If you are getting the "ACTIVATION REQUIRED" message at the top of a Verizon BB 9930 that is supposed to unlocked, the message is misleading.  I eliminated this message as follows.There is a CDMA screen for the 9930.  You can access it by dialing ##000000 from your Blackberry 9930, which will take you to the "CDMA Service Edit Screen", where you can edit some settings.Edit the "Mobile Directory Number" there (it may be blank or the some vestigial Verizon phone number) and enter your phone number that you are using with your SIM card.  This eliminates the "Activation Required" heading at the top.  Be careful not to change anything else on this screen.INTERNET BROWSING is accomplished as follows.  First, you must specify your APN for your service provider.  My service provider is Telna, and their service is very cost competitive and works very well with the BB 9930.  Goto to ''Options'' on the Home screen.  Goto to ''Device''.  Goto to ''Advanced System Settings''.  Goto to ''TCP IP''.  Enable "APN Settings".  Specify "APN: " with the URL from your service provider.  In my case I did not check "APN Authentication Enabled:".  You probably should leave blank "Username for APN:" and "password for APN:"Browsing the internet works quite well as follows:  (1) Use the native BB browser for web access via wifi; the BB browser will refuse to connect over GSM.  (2) Use Opera Mini for web access over GSM; Opera Mini will refuse to connect over wifi.  Install app "Opera Mini" as a browser using "Blackberry World".  Note, you must be connected by wifi to use "Blackberry World".  Search for and install "Opera Mini".  (3)  To minimize data charges, I keep "Data Services" turned off.  I turn it on only when I want Opera Mini to use GSM, and incur data charges.  From the Home screen, goto "Manage Connections", "Network and Connections", "Mobile Network", and adjust the setting for "Data Services".BLACKBERRY 9930 MANUALThe online manual is excellent.  Search forBlackberry 9930 "User Guide" .If you read this far, I hope it was helpful.BTW, I am not affiliated with Blackberry or any phone manufacturer or service provider.