WIll you have to change conveter? Well there is a very slight difference in the charge specs but generaly no you will not.
Expierence: NOT with that specific battery however I did try AGM's once. Was not pleased.. did not feel the added cost was worth the alleged benefits.
What do I use: GC-2 is good but I use flooded wet.
That said. if access to the batteries is an issue AGM is Maintenance free. of all the MF lead acid batteries it's the most maintenance free.
So the choice is yours.. Mine are where I can water them when needed.