Tell me about your automated water change system please.

I currently use a Litermeter III for my ATO, and I have two satellite Litermeter pumps that I'm using to dose two part. My thinking is that if I changed the two part pumps to a water change system that I really wouldn't need the two part anyway. I'm dosing at a VERY low rate. Two gallons of two part have lasted ten months.
I'd like to hear what other people are doing for automated water changes.
Oh yeah, my tank is a 58 gallon and my total system is probably about 65 gallons. SPS, AI lighting.
My thinking is that it wouldn't be too difficult to make the Litermeters change about a gallon a day.  
Keep in mind that I have people watch my tank when I go away in the winter for a couple of months. Currently, while the water is topped off, there is only one 5 gallon water change while I'm gone. I make up that bucket of water and leave it for my neighbor to do one water change. Is there too much to go wrong on an automated water change system? Worth the trouble?
Thanks for any input you can offer.