Heheh! Tell me about it! The thing that drove me nuts was the loud pop when it comes back from hibernation. I still keep it around for memory's sake as it was my first audiophile grade DAP. And to drive difficult to drive cans when I am testing to buy.
As for the Calyx on standby, yes, it is surprisingly resilient in terms of battery life...
How fast is the cold boot up for the M? Also can we just keep it on standby ALL the time?
For me the straw that breaks the dx100 was the boot time (which in itself was a function of not having standby mode withstanding drain battery). I would also have like my 901 to boot quicker but one or half a minute is still okay for me.