Yes, JX is the OEM and EcoPower is a rebrand. Note that servo includes a single plastic gear on the bottom, if you get the JX-HV7232MG then you get all metal gears, it's by far the best servo of the lot, more info here:
https://www.rctech.net/forum/showpos...4&postcount=38
I personally have moved on to AGF servos, which are smoother and offer more torque/speed for the price:
https://www.rctech.net/forum/showpos...44&postcount=6