PS Audio Perfect Wave DAC without the transport

You forgot arguably the most important thing. The PWT uses the I2S interface with the PWD.

I don't have the PWT but to me the PWT would have to beat the bridge by a dramatic margin to offset the loss of convenience of controlling the entire library from the iPhone. Throw in the additional cost of a PWT and for me it is a total non starter. Others may feel different of course.

Goes to show that no amount of engineering can take the voodoo out of high-end audio, and the only way to make good buying decisions is to listen to your favorite recordings after 5 rum and cokes and trust your subjective and fatally biased instincts (works for me all the time).

For the record, the issue is not "I2S" verus "bridge" - the bridge is also I2S. You can see the PWT as a tranport with a bridge build in. Instead of bits coming in through ethernet the bits are read from a disc. The reason it should sound the same is the bridge (either the one in the DAC or the one in the PWT, and in the future the one in the lens) buffers and then completely rebuilds the signal (I2S) and is agnostic to the quality of the bits coming in.

One could hypothesize that the bridge should sounds better because the I2S protocol is very sensitive to transmission and cable lenghts, so having the bridge directly plugged into the data bus in the PWD should be superior to sending the same I2S signal over an HDMI cable. The fact that according to PS Audio the quality of the HDMI cable is paramount is consistent with this hypothesis.

That is exactly the point. Theoretically there is no difference between the bits being read into the buffer (from ethernet or disc drive). So the only difference in SQ can be attributed to how the I2S signal is generated from the bits in the buffer, and how the I2S signal is transmitted to the PWD data bus. On both these counts the bridge has a leg up.

First, the bridge is directly plugged into the data bus while the PWT sends the I2S over an HDMI cable. Bridge 1 - PWT 0.

Second, the I2S is generated from the bits in the buffer is based on the algoritms in the firmware. PS audio is focusing its ongoing development of the firmware on the bridge - sonic differences are reported with new bridge firmware releases. Eventually this may trickly down into the PWT, but for now the bridge is ahead of the firmware curve. Bridge 2 - PWT 0.

I'd trust my ears any day over this purely thoeratical argument, but the point is there is a plausible explanation as to why the bridge may sound better than the PWT.

Of course, anyone familiar with the intricacies of network computing could see the stability issues with the bridge architecture coming from a mile's distance - so many variables not controlled by PS audio.

I suggested to PS audio last summer they should release an asynchronous USB to I2S (using the PS audio I2S interface) converter before the bridge. This would be easy to build, sound as good as the bridge, and give PWD users either a temporary or permanent option to the bridge. It would also open up the big market of computer audio users committed to their PC/Mac based systems to the PWD.

They decided against it because of (commendable but not pragmatic) commitment to a network based architecture.