Power, flatter shooting, larger bullet weights for the 7 08. Fedral offers a 150 gr bullet for the 08. The 243 is close on the ballistics, but the bullet weights are a lot lighter. You can however get a 40 gr bullet for the 243 which could be nice for some varmits.

Speed or Velocity depends on the manufacturer and what bullet is loaded. In almost all cases the 243 is faster. In just one i found the 08 is lsightly faster.

You can got to any manufacturer's website to find ballistic tables on all their rounds.

Unless i was looking at using it for varmits I would go with the higher powered, bigger bulleted 08.

JMO

Steve