Best on board battery charger

[UglyStick]

I posted this in the Bait & Tackle section - 54 views and no replies... Since I think mostly salt guys use that section I'm gonna post it here where I think it's more applicable...

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 individually 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?