Shucks Dougeye, that one is easy to answer. Yes, unless you are strapped for cash then AGMs are worth the extra. I wish everything else mechanical or electrical was so simple.
I think that is too simple. Is like saying "synthetic motor oil is always better." A superior motor oil can be made using synthetic processes but use of synthetic processes is not any assurance of a superior motor oil. Just as the best lead-acid battery they can build is AGM, but not all AGM are better than a wet lead-acid battery.