Flying Saucepan - Here is the objective comparison. Which, if any of the following are of importance to you, only you can judge.
Jetlinx -
British Airways Boeing 757 Level D Flight Simulator qualified under JAR-STD 1(A)
Instruction given by current airline training captains (BA and Virgin)
Instruction given in an airline training environment (BA Cranebank training center)
Cost slightly more than OAT
OAT -
Generic twin jet FNPT II(MCC) configured as a Boeing 737 qualified under JAR-STD 3(A)
Instruction given by retired airline pilots
Instruction given in a flying school environment
Cost slightly less than Jetlinx
Both organisations are approved by the CAA under JAR-FCL 1 to exactly the same criteria and the bit of paper you get at the end is of equal value from either place.