Rex,
Unless you can get extra life out of an AGM or a sealed battery technology in my mind it is hard to justify the cost. A wet cell semi sealed design like any starting battery on the market today holds up well and is virtually maintenance free. I do not check water levels and have never added any to my chassis batteries.
I have had the best luck with buying batteries from a Ward International truck dealership which is a Freightliner dealer here in Pensacola. They bring in a fresh pallet of them and they are built for truck commercial duty. I paid less for their group 31 then I did for a commercial duty version from NAPA which did not last nearly as well. Good to check a large truck dealership along with other sources. Check the battery weight and CCA, the higher the weight and CCA usually the better. Just one opinion...
Later Ed