I'm using the XTAZ14S from Batteries Plus and I like it overall. On the downside, I think AGMs can die permanently with no real warning however (or at least give less indication than a stock Yuasa YTZ14S typically provides). When my XTAZ14S did fail I posted my lame
Info/Questions here.
I did get another XTAZ14S AGM replacement & am still using it. I would buy another one if needed. I think the failure of the first one was likely more due to my charging neglect during a fall period of no riding than anything else. I was typically charging with a lesser 0.75A Battery Tender Jr too.