To Pre-order, or not to Pre-order?

So you think that I should wait to see how the Neu Castle's are doing before I make a decision? I just hate to wait forever, you know?
The 70mm cans are like the same size as the 1515 Neu's, right? If I were to go this way, would the 2000kv be best for the 4s set-up?
Forgot to add: It will be used to bash on street/dirt/grass.

Thanks guys!

-Brett