Sorry to chime in - I read those reviews before I bought the SEX (after already having the Crack+SB).
As noted, different people hear or perceive things differently so I found the reviews particularly helpful as they provided a comparative.
I couldn't, however, find any mention of the SEX being cold, rather I thought he said "cooler but not cold" when comparing to the Crack.
I too would never, ever describe the SEX as cold.
The analogy used as Crack being front row seat and SEX 10th row was a good one for me and this may be what contributes to a description of coolness by some but I am not sure this is the same thing.
In my opinion, it gives the SEX a sense of greater seperation and amazing depth as the review noted, but definitely not cold.
It's similar with "tubiness" which some may associate with being warmer or less detailed.
A tube amp that is detailed and neutral is often described as sounding less tubey, almost solid state (I'm still never clear whether this is intended as criticism or compliment but it must depend on taste).
For me, tubiness is neither the level of detail or warmth, but the liquid smooth delivery which both the Crack and the SEX have in abundance.
In terms of speakers for the SEX, I use mine with headphones and nearfield speakers in a desktop setup (83db sensitivity) and it is currently my most used amp.
I have tried it through my 90db Spendor D7s in my main sytem and was shocked at the volume achievable. It does depends on the size of the room and usual listening volume though.
As for sound, the Spendors can sound lean or even harsh depending on partnering equipment but with vinyl into Eros into SEX, Wow! Nothing lean or cold about the SEX.
