Not in the last 12 months but I switched to AGM's about 15 years ago and it was the best decision I have ever made (other than asking my wife to marry me).
I could not properly keep up with the wet cells and usually had to install a new set every year or so. When I made the hugely expensive leap to AGM I did not think about my batteries again for over 10 years. Yes, the still worked but I was seeing some decrease in capacity. I now have another (cheaper) setup of AGM's which cost about 1/2 of what Lifeline AGM's cost. They have already passed the 5 year mark so even if they crapped out today I would break even. The good news is that they are not showing any signs of deterioration so I am pretty sure my cheap Chinese AGM batteries are going to have been a good choice.
