Sprint HTC One M8 HK edition vs regular Sprint M8 topic

Hi Guys, I just switched from t mobile one m8 to Sprint one m8. There was a huge deal with HTC one m8 HK edition. The cost was only 0 or so. Regular Sprint One M8 was still 600+

Do you know why this phone was cheaper? Will all the custom roms work in this phone? Is there any hardware wise difference? I'm only interested in GPE ROM. Please let me guys. If there is already a topic for this then please help me in locating it. Thanks in advance.