Most seem to get pretty bad reviews...
Current model is a rule http://www.westmarine.com/buy/rule-i...11_330_002_502
I disconnected the auto side last year while on the water and forgot about it until AFTER I put the batteries in last night (new cabelas AGM 22's with ONLY the top screw post (PITA) - now I know why the batteries were cheap and a new model is coming out). Of course after the batts were all tied in and I connected the float I recalled the disconnection when I heard the pump running solid - so out the batteries came.
Here's the other one I'm looking at which is a electro-magnetic type float.