I just wanted to mention that it's clear that you can't go wrong with either of these dacs, owners seem to universally love both and I suspect they're more similar than different.
If you're feeling stuck, you either need to demo both and let your ears decide (AM at least gives you a free trial), or go with @twoch's advice and buy whichever one you think will make you feel satisfied and prevent the upgrade itch.
In the end that's why I got 6 dacs in house at the same time. The experience of trying many different competitors (and topologies) really made me feel much more settled with my final decision. That's another nice thing about using these old dac chips. Once you personally experience their superiority over new technology, it makes the constant feed of new ones less attractive (although I'd still love to hear a bricasti).