Is It Worth Trying a 915 MHz Wireless Link; Such As, Ubiquiti XR9, or SR9?

Elludium_Q-36

Is it worth the effort, in a small city, to try and use a 915 MHz wireless link, as an interface, in a pfSense deployment?

I'm only interested in UNlicensed spectrum, ITU Region 2, U.S.A. (FCC), that allow encrypted data:
http://en.wikipedia.org/wiki/International_Telecommunication_Union_region

I'm not aware of any DECT networking equipment in the Unlicensed PCS band of 1910 to 1930 MHz.
http://en.wikipedia.org/wiki/Digital_Enhanced_Cordless_Telecommunications#DECT_for_data_networks

On the FRS band, what I would want to do, would be considered as a TNC (Terminal Node controller), which is a "No-No"!:
http://home.provide.net/~prsg/frs-faq.htm#Q15

Considering my range of .5 miles, to one mile; that seems to narrow it down to one ISM band, 915 MHz:
http://en.wikipedia.org/wiki/ISM_band

I'm thinking about a Ubiquiti XR9 or SR9.

I only came up with a couple threads on here:
https://forum.pfsense.org/index.php?topic=943.0
https://forum.pfsense.org/index.php?topic=7873.0

It looks like there's a theoretical 54Mbi/s, but I'd be happy with a consistent 5! I'm certainly NOT getting that, over 3G.

I see a list of some of the other hardware I've investigated:
http://en.wikipedia.org/wiki/33-centimeter_band#900.C2.A0MHz_wireless_networking

There are transverters, to put in-line, between a 2.4 GHz 802.11b/g/n router, and the antenna, but they are quite pricey, and you need to tweak settings, such as channel width.

I assumed a 700 mW output from the cards, and came up with an estimated "Approximate Received Power Level" of -66 dBm, using this online tool:
http://n9zia.ampr.org/urban.main.cgi

The endpoint feeding data would probably be an omni antenna, and there are some trees, woodframes, stone/concrete, rebar/metal stud walls, with which to contend.

The end feeding the data could be a "routerboard"…

I'm willing to bet SOME on here have the real world experience.

There is actually an IEEE draft for 900 MHz (902 - 928)/ 915 MHz band networking: 802.11ah
http://en.wikipedia.org/wiki/IEEE_802.11ah

802.22 / 802.11af "White Space"/"Super WiFi"/"WhiteFi"/etc. might be better yet, but it is too new to be affordable:
http://en.wikipedia.org/wiki/802.22
http://en.wikipedia.org/wiki/IEEE_802.11af

Thanks!