I had 1.2.3-beta (don't remember which version) running about a year ago with a Millenicom/Verizon EV-DO USB key running into the little 3G router they sell (which I don't recommend–flaky firmware). I had this set up to load-balance between that and a partial T-1 we had coming in (the rest went to actual DS0 phone lines).
There was a problem with the load balancer losing packets while testing whether the EV-DO connection was up and so it would flip up and down, or just stay down quite often, especially when Verizon's network was under load during rush hour (we're right next to a major freeway). I BELIEVE this has been fixed by the time 1.2.3 went into final release, but I'm not positive and haven't tested it--we dumped both and went to a WiMax connection from a local provider that, once finally set up, has been very reliable. (And why not DSL or something? Qwest/U.S. Worst wouldn't give it to us, saying we couldn't have that and the T-1 running. We're at the very limit of the loop, several miles from the CO and NO DSLAMs in between!)
I guess one problem is, do you really need the hard-core filtering a full pfSense setup provides or do you just need the connectivity? Considering that, by your words, this is in the middle of nowhere, perhaps security isn't important enough to really worry about compared to, say, keeping power consumption low and having a reliable box with firmware that doesn't crash--this last bit being the most important since there won't be anyone around to reset the box! Price tags mean nothing in that department unless you go carrier-grade (expensive Cisco stuff, say).
Mike
