The inclusion of the mid range songs here really made me question what hifis relevance. I have heard both of them and there are many headphones that beat these 2 out of the park for the same price.
These 2 are some of the most claustrophobic sounding headphones I've heard, given that I'm using sony wf1000xm3 tws buds, I had expected a lot more from sony. The 720n is the same price at which I bought my 1000xm3s and there is no comparison between the 2. The soundstage in both 520 and 720 is pretty much non existent.
If blocking out external sound is all one cares about in headphones then go ahead buy it.
But I actually use headphones to listen to music not block out noise, I would have just bought earlier muffs if all I wanted to do was block external noise.
I side tested both JBL Tune 770nc and it out performed even the 720n at the price of the 520n
1more Sonoflow is another one that's miles ahead of both of these.
I think I'm going to start viewing whathifi reviews in the future with a pinch of salt