At Phoronix we do not presently use Serious Sam 2 for benchmarking.
Quake 4 demos can be recorded using the command recorddemo <demo-name> and then to play the demo for benchmarking, timedemo <demo-name> can be used. For accurate results, it's recommended to run the demo at least twice.
At Phoronix with post-Quake 4 v1.2 the demo we use has been recorded Air Defense Bunker (the first map). Purification Center is another level we have used in the past for benchmarking.