Stihl 660 Arctic vs. 390XP vs. 288XP vs. 395XP Husqvarna

IMPORTANT - PLEASE READ!!!
Testing a new ms 660 Stihl for a guy in Nevada, 390XP for a guy also in Nevada, a 288XP for a guy in Idaho, and my 395XP with a big bore kit. This is pretty much the initial testing of the 660 and has carb issues as well as a slight mod that I tried but not really sure if it for the better. Standing alone, it runs pretty good. The 288 has the worst chain but still runs very well. I know the 288 would cut a little faster if the chain was in better condition and be on par with the 390. The 390 and 395 are pretty much dialed in and it shows.
Both the 390 and 288 have a bored venturi and reshaped combustion chamber. They are in a very high state of tune with a lot of work on the cylinders.
The 288 was a nose bleed project. It had to be completely torn down to replace the crank, bearings, and seals. The carb and top end are also new. Gracefully, the owner has been very patient since this project has taken TONS of extra time. I would like to say thank you for the consideration.
The cut started out at 27" and ended up at 32". This means that the 660 had about a 27" cut, the 390 had about a 28.5" cut, the 288 had about a 30" cut, and the 395 had about a 32" cut all measured across at the widest part.
The three small saws are sporting a 115 3/8s driver bar and the 395 has a 125 3/8s driver bar. All four saws have an 8 tooth sprocket.
Take note of all of the above when making your determination on the fastest...
Thanks for watching!
P.S. Cursing to get your point across is not considered more intelligent.............