I was looking for a smaller size than this 9 cu.ft. size but I'm happy that it was available.  I'm grateful that it has an indicator light because I can't hear it running.  Started filling it the next day after purchase and was happy with it keeping the temp below 10 degrees.  If I'm not going in it every other day (garden season), the temp will stay around -4 or -5 degrees.  I haven't notice any changes in the electric bill but this is the height of summertime so it's hard to gauge.  If you have the space don't settle for a smaller size!  I filled this one rather quickly.