Resistor vs. Regulator
Resistors work by Reducing the Volts down from a specified Amount of volts... in this case 12V. The resistors take 12 volts and bring it down to 5. That is what they are made to do... 12 volts and take it down 7 volts. If you put a higher voltage through a higher Voltage will hit the leds and burn them out.
Regulators will take ANY voltage and reduce it to 5V so in theory you can put a higher voltage through and it will only allow 5V to get to your leds. In theory this allows you to have longer runs without power injecting BUT higher amounts coming in can cause a regulator to get hot and eventually burn out so they are only warrantied for anything higher than 12 volts. In the future this might be a fairly big advantage BUT today there is no real testing to see if enough voltage could be sustained to make a difference. The warranty doesn’t cover higher voltage usage
They BOTH do the same job, just in a different way.
A bit more power can go a little further without power injection.
Plug it in the wrong way and your string will burn up.
Put higher voltage than 12 volt though it and you have no warranty
They are cheaper and work very well.
Can’t send higher Voltage through.
Can't go quite as far.