First impressions (latest firmware installed):
1. Listening to Spotify via WiFi is killing me. The connection randomly cuts off. Clicking on other songs while already playing one is often resulting in silence. I am sitting 1m from the router ... EDIT: Trying to listen in another room (one wall away from the router) results in no sound whatsoever, despite the device showing the signal at least at half strength. Youtube is not loading either. Yeah, this is not looking good.
2. The device absolutely can not multitask (not that I expected that, it just caught me off guard that having Spotify sit in the background, doing nothing, would make youtube app absolutely unusable, the frames are literally coming from the past.
3. The first battery run (came to me with 67%) did not impress me. I will see how long it will hold now that I have charged it for the first time. I mostly stream. EDIT: 50 minutes of streaming resulted in 15% battery drainage, the device shows the estimated remaining power +- 5 hours. So it seems that streaming gives you about 6 hours of listening.
4. The sound quality is really good though.
5. The device looks and feels great, the display is beautiful and huge. Craftmanship is top-notch. In this regard, it does not fail to impress.
Right now I am seriously considering sending it back, the sound quality alone can not redeem all the problems I have with it - while writing this piece, Spotify cut off 4 times and refused to switch songs 2 times, I have had to wait 15 seconds to see anything happen. I have a 500+ Mbit/s fiber optic internet with almost no latency.