Best on board battery charger
 

Upgrading the boat and would like some opinions on what on board mounted battery chargers people like. It will be going on a freshwater fishing boat with 4 12v batteries; 2 of the batteries are each isolated from the others and 2 of the batteries are wired together to make a 24v bank for the trolling motor - all of the batteries are deep cycle (technically dual purpose so they get treated like deep cycle) - 3 of the batteries (Interstate) are normal flooded type and 1 (Optima blue) is an AGM.

What's everyone using - what do you like and dislike about them?