One of the problems iriver has in releasing breakthrough products with its attendant price tag is meeting expectations. Invariably, they will fail. Boot up time is just one of those characteristics that is the cost of admission.
The battery life could be longer, but it entirely depends on the files: DSD seems to not only get my unit warm, it sucks the battery life. As to what you can expect, the consensus is somewhere around 8-9 hours on average; I've never really ever measured it myself.
For someone who has never purchased a hi rez DAP, your first foray is noteworthy, not only in its expenditure, but also in the absolute fact that this player represents the
state of the art in sound reproduction for a portable player.
I'm pissed, though, that my unit appears to be malfunctioning ...