Arcam irDAC vs W4S dac 2 vs Bel Canto Dac3

I`m currently running the Arcam dac with no real complaints except that it may be outclassed by the rest of the system. I was just wondering how the other two dacs mentioned in the title would compare with the irDAC. I realize the Dac 2 and Dac 3 were much more expensive when introduced so this may not be a fair comparison but the Arcam is 3-5 years newer  so that may level the playing field.
It would be great to hear from former or current owners with hands on experience. 
The rest of the system consists of Moon CD1 as transport, Node2i streamer,  Krell KRC-3, KSA-50s pre and power amp and Spendor S8e speakers.