A price to pay for such premium, nobody would want to pay for an expensive player without consistent firmware updates/support right?

Honestly speaking yes if your usage and main point of upgrading is that. There are other aspects to look at for the Dune whereby some features are not available in most entry level media players.

Last time I streamed HD contents via wireless on my media player and after a while, my router overheat and my router can be considered half-dead. The performance of my router degraded so much and hangs very often. Since then, I stream over a wired LAN setup.

How high is the bit rate? As long your wired LAN can achieve at least 15-20mbps should do fine for most files already.

Yea, 100mbps after considering those network overheads and such, I am getting about 5-7MB/s. Although streaming is fine for most files I have, transferring to my NAS drive takes a while for large files so I have plans to upgrade my network setup to gigabit connection but will have to see how since a lot of equipments needs to be changed including my homeplugs.