The A1 mini: 180 mm open bed-slinger, AMS lite color, $219, the printer that made Bambu the default beginner recommendation. The H2D: 350 x 320 x 325 mm enclosed flagship with independent dual extrusion, LiDAR calibration, 350C, active chamber, optional 40W laser.
If you are genuinely undecided between them, the realistic reading is: you want a capable machine and have budget. In that case the useful comparisons are H2D vs H2S (same series, $350 less) or X2D vs H2D. The mini is not the alternative; it is a different hobby.