I purchased one of these from Dennis Kirk in late July, 2020.  Same great price ($250).  It has a few glitches but they are easy to rectify and the price is killer good.  It's the second MAC system I purchased.  

The first I purchased from Niche Cycle (full price).  It was chrome.  I harvested the header for my modified stock muffler system.  It worked good but it was a hefty price to pay for just a header.

The second (July 2020 purchase) is black.  I will be using it to start a new high performance muffler project.  I tried the system as delivered to see how it runs.

The one I received may be an anomaly, but it had two significant fit issues.

1. The flange on the header is about 2.5mm too large.  It would not fit into the socket in the cylinder head.

2.  The muffler clamp is too small.  It would not fit over the muffler.

I cut down the flange and used a dyna muffler clamp.  The system fit perfect with those two mods.

With the MAC system, the motorcycle is measurably faster.  Timed runs show a significant improvement in WOT acceleration.  It also seems  to have much better part throttle performance.  Feels really strong at part throttle.  Taking off from a dead stop, cruising, it feels really good.

It is grossly loud.  Like it hurts my right ear.  I can't ride it without ear plugs.  Some folks like the noise, I don't.  So I will be using the MAC system as a foundation for my free flowing quiet system.

If you are into the "noise thing", this is a really good price.

Why are headers so expensive compared to mufflers and why is an aftermarket better?

Thanks for posting @soc. I just ordered mine now. I wasn't planning to do an exhaust change but given its on clearance, decided to put the other mods on hold and pick one up

@dragbikemike how did you trim the flange down? If mine is also too large I assume a dremel would work?

Does anyone know if this comes with a new heat shield like the one directly from MAC?

I just ordered one - the website showed there is only one more left.

This shows the wooden holder.  It allows you to hold the pipe without scratching it up.  Of course you don't want those metal chips in there when you place the wooden holder around the pipe.

How did you get the room to spin?  

There's no way that the supplied clamp was gonna fit the muffler.  It didn't even come close.  It's a top quality clamp, just too small.