James I kinda agree with you... except for one aspect... a good brushless driver can be faster than a nitro in every part of the track... I am racing now and can honestly say it is much better out of the corners, you can get to the next corner faster than a nitro, then there is the straight as well. And if you have a triple jump or something like that and not much space, a brushless is more likely to get enough speed to make the triple, however, it may or may not be faster than taking double then the third after.
The first time I was out racing ever in June, I was in 2nd place out of 7, they were all nitros, I ended up getting 4th because of an unexpected shutdown.
The first part of the race I wasn't doing so well, then I just got faster and faster until I realized that with BL power, I can get away from them out of every corner. I was soon in 2nd place and catching up to 1st place truck.
I will have to agree though, there are some pretty good nitro engines out there that can compete with a BL system when tuning is done right, but not faster.
Finally, yes, you don't need OR want 6s/2200kv setup on the track, you can never use it... heck I use a 1512/1700kv on 6s and it is just right IMO for the track, it has really snappy power, lighter than a 1515, and can beat anything down the straight. I can even beat a Tekin (4s, 1900kv) BL Eight that a guy converted since he saw my Revo, which I don't understand?
There are other things that need to be considered as well, like going from 645mg servo and bow-tie MT tires to 7955TG and Crime-Fighters LPR was a HUGE difference for me around the track, one of the reasons I did so well at the last race. I am going to get some AKA City Blocks soon, that should be another big jump.