Based I what I heard in this thread the AGM batteries makes sense in a DD where you just drive it and let the alternator do the charging. My wet cell batteries in my cars usually last about 4 years. If the AGM's last 8 years and they are twice the price that makes sense. In the MH I maintain the batteries much better than my cars so my 2 Sams club 6 v house batteries are 12 years old now and still doing their job. The Walmart starting battery lasted 9 years, not because it was better than my previous Trojan marine battery which lasted 4 years but because I just charge it when I charged the house batteries. If you look at cost/amp hr I think it would be hard to beat the GC batteries from Sams Club or Costco.