Luxman integrated amps can sound overly smooth (e.g. their class A amps) and need to be paired with non laid back speakers.
The newer "Z" integrated amps are more detailed and sound excellent.
Newer McIntosh POWER amplifiers are as smooth yet detailed as anything out there- the midrange is the star- such bloom and clarity- is what sold me on them.
Their preamps and integrated amps tend to be softer sounding in the treble but still sound amazing when paired with the right speakers.