On the subject of survivability in an IADS then MQ-1 did very well over Serbia, Kosovo, Iraq and Libya; all of these had fighter aircraft that had to be defended by Allied fighter sweeps. It also allowed other defenseless aircraft like Nimrod, Sentry, Sentinel, VC10, Tristar, Canberra to operate once protected by a screen of OCA and/or SEAD. I see no diffence for our current flock of RPAS save for the RQ-170 that seems to operate in IADS quite nicely (including operating over Pakistan undetected and unmolested!).
So, don't believe the naysayers, they have no clear evidence to back up their claims apart from a single MQ-1 that was shot down trying to exchange shots with a MiG25 over Iraq - unfortunately, the Hellfire guided towards the contrail of the MiG but the MiG's Radar Missile guided to target! Or the single Hermes 450 shot down by a Russian MiG29 - the Georgian "operator" did nothing to react apart from watch, why? Because he was trained as an "operator" and not as aircrew. He could have descended in a tight very slow spiral and hid in Main Beam Clutter, but he was probably never taught this as an "operator".
Finally, RPA are expendable. The average RPA costs around £3-7M each depending on payload and performance. The average manned fighter aircraft costs nearly 10 times that. So if you only lose 50% of your RPAs vice that of your manned aircraft to achieve your strategic aims, plus the added bonus of no loss of life, then you are on a financial winner.
The B Word