I just got my W2 today. I just spent 1.5 hours doing some A/B/C/D testing using my EE Odin as the earphones, iPhone and Tidal as my source and I compared Lotoo PAW S1, LPW2, Chord Mojo and Chord Hugo 2. To me, the sound signature is so obvious that I don't need to do much more testing. I know where it fits.
The LP W2 is a direct upgrade to the Lotoo PAW S1. It has a very similar transparent sound signature, but it just does it better all around. Whereas the S1 sounds boomy across the frequency response spectrum at times, the W2 is very tight and clean. The difference is bigger than the difference between the DragonFly Red and DragonFly Cobalt. You need a good ear to hear the difference between the Red and Cobalt. Anyone can hear the difference between the S1 and W2. I forgot to bring the DragonFly Red with me, so I can't compare it, but I prefer the S1 to the DragonFly Red.
To me, the LPW2 is comparable in quality to the Chord Mojo for driving IEMs. I only brought my ZMF VC with me on this trip, so I will test the driving power of the W2 for high impedance full headphones with it. I would be surprised if it did very well especially given the earlier description of the W2 and HD800. My guess is the Chord Mojo will have the power advantage as it can drive the VC.
The big difference between the Chord Mojo and the LP W2 is sound signature. The Chord Mojo has a warm signature whereas the W2 has a much more transparent signature. Depending on the IEM you are pairing it with, one or the other will likely sound better. To me, the Chord Mojo did better on tracks that had more of bass emphasis given its warm sound signature. The W2 did better with Classical and acoustic music. Anything that favors sound stage and transparency.
It was a complete knock out with the W2 vs. the Chord Hugo 2. The H2 was better in almost every way especially with respect to resolution; and detail and clarity.
More later as I get more ear time with it. But, this evaluation was very straight forward to me. I don't expect my opinion to change much. I look forward to pairing it with the Hugo 2 and C9 to see how far this dongle can go.