It may do well against Russian drones but what about against American
designed planes using American tactics for SEAD missions and the
assoicated counter-measures? The track record of Russian SAMs against
our planes is not impressive but in all fairness rarely if ever do our
SAMS go up against Russian aircraft. Let alone how often are the
abilities of a new weapons system far over-rated...we do it all the
time to secure funding from Congress. I'd like to see this system
against a F-22 or perhaps even a B-52 firing stealth cruise missiles
from far outside its range. Get falcons to fly in as a feint and then
once the SAM radar lights up highlighting its position the cruise
missiles are fired...memorize the rough location of the radar and
cluster bomb the area etc...no need to kill the missiles...just the
radar/command trailer.

The S-300PMU2 Favorit can engage targets flying from 10 m to 27 km
above the surface at a speed of up to 10,000 km/h. It is claimed that
it has a kill ratio ranging from 0.8 to 0.93 against aircraft and from
0.8 to 0.98 against Tomahawk-class cruise missiles.

more.
http://www.globalsecurity.org/milita.../s-300pmu2.htm