AGM Batteries

Any current thoughts on AGM batteries?

I tried a Concorde 35AXC about 8 years ago. It lasted about 30 months
for me. Wet batteries seem to last around 4 years.

However, there was some corrosion damage from the wet battery last
annual, and so I'm rethinking the AGM option. I might be willing to
trade some battery lifetime to avoid potential airframe issues.

Anyone have a preference on Concorde vs. Gill?

tia