Used Windows Phone purchase and set-up

I purchased a used Samsung Focus, locked to the Rogers network, recently.  OS was also not up-to-date.  I made sure the phone was Samsung rev 1.3 (how?) as I heard reports on Windows Weekly that rev 1.4 could not update to Mango.  Here's my experience:

• Downloaded Zune software.  While it has a very slick UI (compared to any software, but especially iTunes), updating over the air, as per latest iOS updates, is much more friendly
• Connected phone using USB cable, checked for Updates
• Found Update 7403, began downloading and installing.  I went to do something else
• For at least half-an-hour, Zune is indicating something about "checking for space".  I hit Cancel
• Re-check for Updates, found Mango (7720).  Installed
• Then Zune found Samsung Update for Windows Phone

I was glad I didn't have to do anything silly like suddenly disconnecting the phone as per http://www.winrumors.com/how-to-force-official-windows-phone-7-5-mango-update-onto-your-device/.  Also, all of this was done with a phone without a SIM installed yet.

At one point, don't remember what phone was supposed to be doing, the phone went into a "Download mode" with a yellow warning triangle saying it would be done in about 10 minutes.  Time went by and it was stuck that way.  Eventually I took out the battery.  After starting back up, everything was fine. 

I also put in a Kingston 4 GB MicroSD that I purchased a few months ago, not heeding the warnings about incompatible MicroSD cards.  I followed the instructions included in the box with the Focus and everything went well:  the phone now has a (measly) 10-something usable GB (12 GB total).

To try things out, I put in a Bell SIM card from my Mi-Fi device.  The phone prompted me to enter the PIN to unlock the phone.  I ordered the unlock code from http://www.cellunlocker.net/ (providing the IMEI code for my phone) for $7.99 USD and after about 9 hours (it was a Saturday), I received the unlock code, which worked!