I know the first is considered rapid and the second is considered blitz, but, really, which gives more time to think?
5|5 is faster for almost all games compared to 10|0.
Assume a 40 move game. That will give (5 seconds) * (40 moves) = 3min20s extra on each players clock (so it is equivalent to a 8min20 time control for 40 moves). A 5|5 game can last longer than a 10|0, but these are the exceptions. Overall, 10|0 is slower.
I know the first is considered rapid and the second is considered blitz, but, really, which gives more time to think?