The unlocked SIM means that you will be able to get the device without a contract but you also have to pay the full price too which is $649. This developer edition is expected to be released in limited quantities is US and will only be available to those with US zip code. So if you are outside US you may find it difficult to get your hands on this beauty.
For those who are still unaware of HTC One, it is the new flagship device recently released by HTC. It is powered by a Qualcomm Snapdragon 600 chipset along with 2 GB of RAM and features a beautiful 4.7” Full HD display. HTC has used 4 Megapixel camera with “Ultrapixel” technology for better low light performance and low noise levels. It runs on the Android 4.1.2 Jelly Bean with HTC’s latest Sense 5 UI on top.