Brushed vs brushless alternator

I am most likely going to open a can of worms on this subject but I would like to get some opinions as to the pros and cons on which type of portable generator alternator is better, brushed w/AVR or brushless capacitor regulated with respect to THD, motor starting capabilities and maintenance.
 
Any information would be appreciated. Thank you.
 
 

One thing to consider is that electric motors can have an inrush current that can be 10 to 30 times the nominal current rating listed on the motor.
 
A good example is the 15 running amp 3 hp compressor motor I have here. Most would assume a 30 amp 5KW generator with 8 KW surge would be able to start it under load. Well it won't, matter it will fried the motor. I know as I fried one my compressor motors on my air portable air compressor trying to operate one while my shop had electrical service.
 
For THD I haven't never ran spectrum analyzer test on one either type.

If this is case then it comes down to engine hp and how small of a governor droop it has. Larger engines handle sudden loading better. As do V twin over single cylinder engines.