I changed out my bathroom El Cheapo exhaust fan for a Hengs Vortex 2 fan. It was a very simple swap out and installation and so far works great.
Just for curiosity I tried the fan blade from the old El Cheapo bathroom fan on the stove hood exhaust fan and yes with the more blades the fan runs much quieter than ever before. When I get the PWM speed control installed it should be really good and run even quieter at a slower speed.
I also removed the very cheap rattly plastic damper at the same time it appeared to be doing absolutely nothing but making more noise. Will install screening over the vent if there is any indication of bugs getting in.