Arcana is easier to handle. It's just a run of the mill weapon, but it can do above-average damage if used well.
It's charge shot offers better knockback to the Alchemer line.
Though... Arcana just feels lame. Three shot with no outstanding features. Unless you count the feature of not having outstanding features as one.
Alchemers involve your stupid switch shooting. I don't have the dexterity and speed for that sort of crap, but if you do then that's good for you.
Capable of ricocheting standard fire at a high enough star level.
Has some pretty lame knockback ability and it's pretty much a toy gun that shoots ping-pong balls without switch shooting.