Just picked up Reminders Nano as well. So far it's awesome and definitely the "missing Apple app". Only have 2 gripes with it:
1) as other said, can't sort lists, and
2) the text is jumbled up is you have large reminder name. So if the reminder item is only one word like "milk" it's fine. But if the item is "pick up a jug of milk from the grocery store" the text is going to be off the screen. Not sure a bug or Watch OS system limitation.
Yeah it needs to truncate after two rows - three rows of text doesn't fit.
Otherwise it's great.