For whatever it's worth....I contacted them and got the following answers to some questions I had. Simplicity, functionality and SQ are all the matters to me...so here are my questions and their answers:
Hi,Thank you for your email.1. Does it have an equalizer...and if so...can you make manual adjustments?
2. Can you set up playlists?----Yes
3. Does it come with an user manual?
-----You can download the user manual from our website after a few days.
4. Is there any satisfaction guarantee period...IE, 30 days and money back??
-----14 days money back guarantee.
5. Does it record from USB on computer?----You can transfer data into the DX90 via USB.SincerelyiBasso Audio
Sounds pretty good to me.....all for $419, I believe