I have the 3500 Predator. Fairly new with only 19 hours. I did the break in oil change at 5 hours and put synthetic oil in. Runs very quiet. At full load it is quieter than neighbors Honda by about 2db at 25'. I use it with my TT and it runs the entire TT including a 13,500 AC.
I also have a Champion #76533 3800 / 4750W dual fuel genny. It is almost 10db louder than the Predator at 25' but still tolerable.
I bought these electric start gennies because I can't use pull start due to rotator cuff injury. I use electric winch in the garage to lift them into the pickup bed and run them from there.