High end high quality int. amp for low level listening


Hello to all Audigon members.  I'm quite in a dilemma weather I should upgrade my amplifier. Currently I own Pathos classic one MK3 driving Sonus Faber Sonetto's speakers, and I must say I'm very happy with sound filling my 35 square meters room. However, it's known that the speakers are power hungry as they rated at 86db sensitivity and 4 ohm impedance and I think they will surely benefit from a bigger power supply. With all that being said I'm not sure if I will hear any improvement mostly because 90% of the time I listen at ~60dBs SPL. My budget is around 5k $ and these are the amplifiers I've been considering:  Hegel H390, Anthem STR, Cambridge Audio Edge A, McIntosh MA5300/MA252, Accuphase e280, Rotel Michi x3 or used Pass Labs INT 25, Mark Levinson 5805.

What do you think guys, will any of the amplifiers make ay difference at 60dB SPL ? 
celestial__sound
At 60 db liwstening level , you are only using less than 20 watts ...if that. a $300 Schitt Lokius will do the job nicely. ......or the $150 Loki Mini+ will also work just fine.You'll EQ the lower listening levels to exactly the sound you like without spending $5000.
Wow!  Great Feedback from All!  Very Educational, especially with "each of our ears, hear and appreciate different tonalities and soundstage's differently.."   Thank you to Each!
Get a pair of subs to fill in the sound stage. Makes a big difference at low or higher volume levels. 

What you need is an integrated with loudness control, for low level listening and still get the punch. Accuphase, Luxman and/or Yamaha would do. 
These speakers appear to be bi-wireable. Bi-amp them, if possible. The majority of the listening here is around the same dB. If you happen to have another amp available, hook it up. The results may be surprising.