I use a Timeline brand CG-1000 electronic air filter in my air handler. Electronic air filters, as opposed to electrostatic ones, filter air using a charged electrical grid plus filter pads.

I found mine a bit of a struggle to replace, but it has kept my coil completely clean now for 3 years. I just vacuum it monthly, and change the pads about every 3 months. I had to replace the filter assembly after 3 years as the thing failed on me.

I would like to hear your experiences.