First: does the router work with bus-powered external drives ?
Answer: mostly works ok with 2.5" usb disks, not always.
Second: does the router know to spin-down the drive when it's not used (ie. put to sleep and wake up when needed) ?
Third: will the download speed be any better ?
Answer: No, but do a search on 'hdparm' in the forum
So, will the external hard-drive with the better write-speed improve this ? What's concerning me is that maybe the router itself has a slow CPU or some other resource that limit transmission's download speed.
Answer: maximum write speed is about 2,5 MB/sec (wired)
(due yo slow cpu i assume)