GreatBear,
from the ACARS positon reports the average Ground speed up to 2:10 can be derived at ~470kts.
I have difficulties to see a method in an Airliner at 35kFt to decellerate in such a short timespan that the average speed would drop to 200kts (except immediate loss of a Wing or an attempted loop). with normal and reasonable control input that should be hardly achievable.
(Even the guys who tried to break the high altitude record with a Canadair RJ a couple of years back who deep stalled it all the way down still travelled quite a distance before hitting short of the alternate airport).
However, that wouldn't rule out a position close to LKP though.
Taking into account that the general attitude of the aircraft presumably was out of control, it is even rather unlikely that the flight path in the final 5 minutes was straight.