In the Deathwatch core book it gives the suggested XP award as 500xp per 4 hour session for each player. It then goes on to offer the detailed chart based on challenges and objectives.
If you're using the detailed list do you divide up the xp between the members based on them all completing the objectives etc or do like to award to the member who did the deed, i.e 'Here's +175 because you took off the Hive Tyrants head'?
How do you like to award XP?