for your trolling motor or main cranking?  any feedback?

Don't use if for a cranking battery.  You will need a gel charger, they are much more sensitive to charging conditions, even more so than AGM's.  A good gel charger is going to be fairly expensive..  You will not get the run time a good flooded cell battery and not many will give the run time of the better AGM's.   Properly charged, they will give more charge cycles (longer life span) than the AGM's or flooded cell batteries.

Have been using Dual Pro AGM's for 3+ years and haven't touched them. They are dual purpose (deep cycle/starting) and have at least 300 trips on them now. I run a TR20 w/ 225 Merc Opti and MK Max 74. I am using 2 LS3100's for trolling and a LS2700 for cranking and accessories/pumps. You can check their specs at http://www.dualpro.com/lightningseries.htm. FYI, they match up fine with the Dual Pro charger that came in my Triton. I believe any charger that will put out 10-15 amps will charge them fine. If you have questions regarding charging you should be able to contact them via their web site. Very good product IMO.

Word of caution!! NEVER USE JUST ANY CHARGER TO CHARGE AGM's or Gel's. You have to use a voltage controlled charger that does not charge at more than 14.4 volts if you want to get a reasonable life from them. You standard transformer based chargers that Sear's and everybody else in the world sells are not voltage controlled. You use a charger that specifies it's made for AGM's and has an AGM mode. This is also the case with Gel's.

Actually you shouldn't use those things everybody's been using for any battery you are going to charge more than a couple of times if you want to get full life from them. Those and most standard chargers can reach voltages well over 15 volts and over 16 volts for larger chargers, this is harmful to any battery made. Even your deep cycle, flooded cell batteries should never be charged at more than 14.6 volts. Well, actually not battery made should be charged at over 14.6 volts.

I know many will say they've been using them for years.  I know, my grandpa used them, my pa used them and that's goodanuff fur me.  Just shows they didn't know any more about batteries than you.

Until bass fishermen and trolling motors came along, there was not real market for the proper type charger and those things were cheap and worked fine for an occassional charge.  For the past several decades, your automobiles however have always regulated the charging voltage to approx 14.6 volts.