Just got 6th on 4-5X this without hackers on XBL.
Times are as followed from ranked downwards: Other times are clearly hacked: 0.01. 2.00
13th: 6.35 <- Me
Just tried that out of curiosity and got a 4.76s. May have to go and see if I can get nearer 73L
On the PC version you might be playing it, I am on XBL. :)