Is louder better?

The room will have a say too.
Low volume works well with bad rooms/very little acoustic treatment. 

You can listen louder and longer in better rooms.
There's a sweet spot in my room probably because my room is lacking. But at least I can listen well within my range.

I tend to listen high 60s to high 70s. Any higher is disturbing.
Have a pretty refined $130K system and cranking it up does not necessarily distort but my ears seem to not like it louder. I may have inadequate power.
My speakers are 91db and minimum impedance 6 ohms and my amp is an Atma-Sphere M-60 which is 60 watts. I just rolled in NOS output tubes and the power is boosted to 80 watts. I clearly hear louder more comfortably. My speakers do like more power! Am waiting on Speltz Zero Autoformers which will change the impedance and raise to power to about 100 watts. Now anxious to hear even higher levels!

@noromance If you’re still hearing OK after the Jools Holland piano wank at top volume, things are going to be just fine!

Dear @syntax : With the same recording each room/system has its " perfect " SPL to listen it where it does not matters that you put the SPL higher you can't listen more detail.

All room/systems has a threshold about that can be as wider as the quality levels of each one room/system.

Now, in any room/system we can make that threshold wider about SPL if we puts at minimum all kind of distortions/noises developed through the room/system.

But yes you can achieve more details with higher SPLs if you are out of that threshold stratting range. In the other side if you are out of the threhold to range not even you will have more details but the other way around.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

Search "Equal Loudness Contour". We don’t hear everything equally well at all frequencies. Really low bass and really high treble have to be fairly loud to hear well. This is why the Loudness switch used to be so common. At low levels we have to turn up the bass, and the treble, to have them sound right.

+1. Ignore at your own peril, unless your system is challenged at higher volume levels.

DON'T Click on @dastenpen56's link. It is spam.

dweller,

it is not my experience that all systems sound good at moderate levels.

The best systems sound great at moderate levels.

Mediocre systems need to be cranked up to give the impression of sounding better, all they are doing is amplifying everything that’s wrong with the system. They are just louder. 

Think ghetto boom box blasting out of someone’s car trunk as they are driving by. Loud? Hell yeah. Better? They don’t realize - or care - that 95% of what they are listening to is distortion and the sound of their car’s body vibrating.

10' by 13' room...somewhat nearfeild listening in "early am" can be more enjoyable than louder in that size room.

What??? 

i find that if you have good equipment and a lot of power, i hear sounds that you would'nt hear at low volume!

Louder to be louder is not better, but I certainly find that getting volume in the area to reproduce the event as recorded is most enjoyable.  No doubt that is is nice listening at lower levels if your system has the resolution to reproduce low level detail at low volumes.