This. After using Advantage2 for 10ish years I can't really go back to a flat keyboard. I liked my Keyboardio Model 1 but the Advantage2 is just more comfortable.
I love the idea of customization but the flatness has me looking at all these as non-starters.
I hate to add to the Advantage2 fan club, but Kinesis absolutely knocked it out of the park in terms of ergonomics. Makes constant typing ridiculously comfortable.