I recently set my iPhone 5 to backup via iCloud, and it said the backup size would be 1gb. It finished in about 1 minute. How is this possible?? Can I be sure it uploaded the whole backup?
Yes, you can. Also don't forget that it backs up daily as long as the device is plugged in and on Wi-Fi. You can also do a manual backup from within Settings>iCloud>Storage and Backup if you feel it didn't complete.
I believe that Verizon FIOS can move a GB that fast, although the plan that the average perosn would get, it would take closer to 2 minutes to move a GB. However, the WiFi would be the limiting factor in that case and you would be looking at a few minutes to move a GB of data over a perfect WiFi setup.
I am convinced when you delete something it does not go away and it is cached.
I had a CD of my friends band at 128Kbps that I ripped years ago. It was backed up to iTunes match. Last year I started upgrading all of my CD's to lossless. I reripped this CD and it uploaded in like 10 seconds to iTunes match. As a taste I deleted the files from my computer and the cloud claims that the files are 256Kbps but I don't buy it. There's no way you could upload that entire CD that's in lossless and convert it to 128 in that short of time.