TRN BT20 pro or TRN Scallop

Im a newbie in regards to Iems, I just got a Red Zero and Im thinking that I would like a Bluetooth experience when I need to charge my phone and can't use the USB port. I have the opportunity to get these two for a good price in China and would like to hear your opinions about these two. I saw many comments saying that BT20 is better than BT30 and the price of the BT30 is also higher than both so I will not even consider it (its not even showing up at the original store on taobao for me, I can only find 2hand). Scallop just came out so Im not even sure if anyone had the opportunity to test it yet but it seems interesting and for the price, a better choice. Which one do you think its better?