Between N150 and N10, I would choose N10. For the money, N10 is pretty darn good on used market. N10’s replacement N200, is better in more than few areas. If you can afford it, go for N200 and call it a day. Aurender offers support for both Android and iOS. One important consideration, ROON is coming to Aurender and older generation models like N10 or N100 will not be compatible with ROON. Regardless of ROON support, their Conductor app is a robust app offering integrated browsing for Tidal, Spotify and Qobuz.
Both W20SE and N30SA are prime examples of a SOTA streamer, which one sounds better is very subjective and going to come down to rest of the system. I had them both in my home for extended period of time and I chose to go with N30SA.