Seeking an advice on Bel Canto 1.5 Vs 2.5

I recently bought the Bel Canto DAC 2.5 and compared it with the DAC 3 in my blog here.

They are very similar but the USB implementation in the 2.5 is definitely better.
However, they are not as good as the SPDIF inputs in both of the DACs.

I am interested to find out too. Hope users who has experience with Bel Canto Dac to comment.

And how they compare with the wyred4sound dac 2