I like the dual pro products; I've had others, and I think this is one of the best. I currently have a 4 bank (15 amps each) for a 36 volt system with a starter battery. Leave it plugged in year round; I'm now in my 5th season with these batteries (3 trolling batteries are AGM, starter is a wet-cell) with no problems, fishing 30-40 times a year. I think the only material difference between the Professional and Sportsman series is the number of amps per bank.
I got my first one when my old system (minn kota system, I think) was recalled for safety reasons and they replaced it with a 3 bank Dual Pro. When I got my new boat, that's what I put in and so far, so good.
Pro Charging Systems