To be honest I never been to a track to where I seen the 7 port stretch its legs all the way. Its an awesome mill just on smaller tracks I see no need. My 5 port needed tamed in truggy and buggy and I am just getting my 3 port set up right now 6.5mm restricter 70% throw both my mills are modded though. My 5 port I had 50% throw. The coating is Titanium nitride awesome stuff makes internals last for ever. Usually found on 4-$500 mills.