Allulose is about 70% as sweet as sugar but tastes much more like sugar than the other sugar alcohols. Allulose caramelizes (tho you should not try to make caramel with allulose. (you've been warned.)) It dissolves much better than erythritol. Allulose has a consistency more like dextrose than table sugar. More like a powder. It behaves more like sugar in baked goods.
Erythritol has a kinda minty aftertaste.. like on the exhale that can be unpleasant if it's not overpowered by something else.
All that said, I still prefer an erythritol + monkfruit sweetener in beverages. Erythritol is easier on my stomach in larger quantities.