Fobs,
Re the power output - specs for the 520+ are
here, and for the 900AP+,
here.
Note that the D-Link specs for the 900AP+ say an antenna gain of 2dB, nothing quoted for the 520+, yet, in appearance, they seem similar. On another site which quoted D-Link specs, I saw 2dB for both antennae, so who knows?
It seems I'm a bit hobbled in my options with the cheap USB modem I already own, but I'm pretty sure now that I can make the 520+ do what I need it to do. Just hope it will penetrate my paper walls
. Slant range to upstairs may be a factor as you've identified, but as I say, my house is not of the 2 foot stone wall variety. Timber frame and plasterboard walls, timber trusses between floors with plasterboard ceiling downstairs and timber floors (actually, compressed chipboard) upstairs. 100 metre indoor range is in the specs, so hopefully my hacienda will not present a problem.
The kit arrives tomorrow. Will let you know how I go. And thanks for the tip re software installation.
Cheers
AA