More consistent layout and whit background where needed
Added Gary's wishes:

Slide 5: (Difference)
Perhaps reveal picture + half the table at the same time (so I have to repeat less)

Slide 8: reveal risk one at a time

Slide 10: small cluster
Reveal last part – “Great for..”

Slide 15: as discussed – large train diagram
Remove text

Slide 17 (text replaced with):
Passengers board carriage unattached to train
Hope no one notices the flaw in our analogy :-)

Slide 18: (text replaced with):
Count before and after boarding train to determine "last" thread
NOTE: Not to be confused with the Counter data type in Cassandra!

Slide 19: (text replaced with):
Any action on train requires cluster wide locking to ensure consistency!
Some more visual enhancements