Why I Don't Like Evaporative Coolers

At first I thought quite highly of my evaporative cooler (swamp cooler) but then I lived with it for a while. I'll start first with what I dislike about it.

• It doesn't have a thermostat. If I was to install one it would need to be some distance from the air vent to be effective. Unfortunately the control is directly underneath the vent so installing a thermostat would involve non trivial wiring. Due to the lack of a thermostat I generally have two options: 1. Let it run all night and wake up freezing or 2. Turn off before bed with not so cool temperature. I also question the practicality of a thermostat since if it turns on when there is no window open, the motor will strain and possibly overheat.
• You must have a window open during operation. The opening and closing of windows gets tiring. Of course the air only goes where there is an open window. Open the windows too much and hot air invades the house; too little and you strain the fan and limit cooling. It has to be just right for optimum cooling. This is a pain.
• It only works when the humidity is low. There's this thing called wet bulb temperature, which I won't attempt to explain here. The wet bulb temperature is what dictates the performance of the cooler. When the humidity and temperature rise, the capability of the cooler to cool diminishes. We've had plenty of humid stretches where the house is not being cooled and just gets humid ~60%RH, which is a danger zone for mold/mildew, not to mention at the fringe of comfort.
• Coolers require a fair amount of maintenance. The pads need to be replaced once per year. The pump filter often gets clogged with the aspen fibers. The basin collects all sorts of dead bugs and aspen fibers and needs to be cleaned out. The water shutoff sometimes doesn't shutoff at correct water level and overflows, wasting a tremendous amount of water until resolved. It requires winterizing in Fall and Spring activation, in most climates. The cooler, like most, is installed on the roof, which is an additional annoyance for maintenance.  This all adds up to a lot of maintenance for a relatively simple device.
• Noise: it's a bit noisy on high and rattles the ceiling
• It's quite breezy under the vent. Unlike an AC system, all the air of an evaporative cooler exits through one vent and the blast of air you get by walking under it is sometimes annoying. Additionally the floor under the vent is prone to excessing moisture - bad for wood floors.
• It's ugly and visible from the front of the house

What I like about it

• It does humidify the house. I like to keep it between 30-40%RH but sometimes it goes up to 60%
• It should in theory use less electricity than an AC unit but I have not been able to verify.
• It's nice to get fresh air in the house

Update Sept 2012 - I got AC and promptly had the Swamp Cooler removed. A roofing company removed it for only $250 and patched the roof.