I'll add my thoughts. I have a Wiim pro, a Zenith Mk3 and a Denon something or other.
Objectivist data seems to indicate they all should sound the same. To my ears they don't. Now, is my perceived difference worth the $? for me it is. Have not checked the specs but perhaps this relates to the size of the buffers?
In the end, IMHO, the biggest factors when choosing a streamer are which sources are handled (natively or through work arounds) and how friendly and useful are the apps.
I like the Innuos app and I also like the Wiim app. Innuos does not stream Amazon HD thus I keep a Wiim for that on my main system.