I've been using the DX120 for 2 weeks now and its battery quick charging scenario has already damaged my lipo battery noticeably.
After the first four recharges - each lasting exactly 2 hours - the player ran for more than 14 hours in SE mode with my KZ AS10 inears.
The power bank never turned off after the recharge process is completed.
When i charged the player for the first time overnight (at least 7 hours connected to the power bank, the charge bar indicator needs 45 minutes to change from 100% to 99%.
Unfortunately the player only runs 7.5 hours in SE and 6.5 hours in balanced mode from that point on with the AS10.
I am also disappointed about the quality of the keys - they have different pressure points, the start/pause button has almost none.
Protected by the included cover, the DX120 can hardly be operated. (longing for the DX90 keys - they work perfectly from the first day on, also with my beloved silicone cover)
The Shanling m5s, which I bought for comparison, needs 3 hours of charging time, but it runs more than 17 hours in SE and 10.5 in balanced mode with the same KZ AS10 headphones.
Apparently, I will have to send the DX120 back to amazon.co.uk.