If you have a quality DAC the Wiim mini does everything you need for $90.
The features they are adding are really unneeded.
The Wiim amp is OK. But you can easily use a better quality amp with the Wiim mini.
The Wiim Pro Plus is nice but if you have a quality DAC like the RME ADI-2 you're still going to use it's loudness feature, balanced outs and such so you end up using the plus with optical out just like the mini.

The Wiim Ultra will give you a screen but those using Audirvana on MBP don't need it anyway...
Bottom line - New Wiim models raise price for solutions that can be done better with a separate DAC and amp.

The Wiim mini is the best value and actually all you need for streaming.