I think the final assessment of the firmware change should wait at least 200 hours.
Some with venus may not yet be at the level of 1.8 or 3.7 (if I followed well, Pontus should be there with 1.4). The result of 3.7 and after running has clearly the most natural and real sound I have heard. This is so true that leaving a real concert, I immediately started my dac and integrated and could hear the same sound (piano, same brand)
It is certain that the new firmware reveals a lot of details and maybe it also reveals details that may have gone unnoticed before or that was masked about certain elements of the chain! (to be clear, you should test by changing certain elements)
I take an example, auralic has a rather cold and detailed sound (see analytical) (known) but with certain dac, the sound might seem soft with a little less details while with a very transparent, natural and detailed DAC, The "coldness" of the auralic could be unpleasant (by changing auralic with a less cold and more natural streamer, the sound finds all the qualities and more, since more details, precision, 3D image larger and deep and a presence remarkable natural). Of course, this could be a cable, HPs or feet under the dac etc... ( e.g. I put SSC Netpoint 300 instead of original parts and this made a big change into the sound - As well, I replaced high-end hp cables by Tubulus concentus high-end cables and the sound got a big improvement into medium, deep and precise basses as well nice detailled trebles removing all harshes I could find previously -( all went neutral, big 3D - changing power cables provided an improve into quality like the HP cable change. Now v3.7 put the neutrality far forward with the best real, natural sound I could hear ).
For the great sound and step forward into high quality with high natural and real sound, I say BRAVO ! congratulation to the work done by Denafrips and Alvin because updating firmware when no automatic internet link with included process exist is a big chalenge.
Some issue already exist and hope a correction soon.