I wouldn't put a lot of stock into either of those two reviews.
As someone who owns the Serene, I'm just saying.
@jnds As someone interested in either the Serene or Athena I'm very interested to hear what you didn't like about the Serene, where you felt the two reviews listed above were incorrect and whether your thoughts have changed with more playing time on the Serene.
There doesn't seem to be a lot of feedback on either of these pre-amps yet. From Srajaen's reviews he seems to like a very fast, detailed "Swiss sound" even at the expense of body, weight, organicness etc. For this reason he slightly prefers the Kinki pre-amp over the Athena. He also slightly preferred the W4S STP-SE 2 over the Athena, saying that the Athena was slightly less overtly detailed and fast but had more body.
I've not been able to hear any of these pre-amps yet but reading between the lines my hunch is that the Serene's character would be closer to the Kinki and that I may prefer the extra body of the Athena. I am coming from a fairly neutral, non-tubey sounding tube pre-amp that is single ended only. I'm looking to move to a fully balanced pre-amp (as the Holo Spring DACs are known to sound better from their balanced output and my power amp is supposedly more dynamic from its balanced input) and also to reduce the amount of gain in the system (the Athena is unity gain).
Although my tube pre-amp does not sound "tubey" in the sense of being lush, euphonic etc, it does have a wonderful 3D, organic sound with great presence. I'm hoping not to lose these traits but to perhaps gain a lower noise floor with the attendant increase in detail and dynamics but not a cool, lean, analytical, super fast type sound or lacking drive and dynamics.
For these reasons I currently feel that the Athena may best suit my preferences/goals and have not pursued a fully passive pre-amp/attenuator or the Benchmark LA4, Topping Pre90 or W4S STP-SE. I've noted that some people purchasing these options have missed their tube pre-amps and returned to them.