I am also in the Y is ugly group, my personal opinion of course. I even think the Model 3 looks bad when you look at it straight on over the front hood. I quite often see model 3's from a distance and think they are a VW beetle at first (not exactly flattering IMO). But all other angles I like, and everything else about the car I love, so I placed an order. Having said all that, Elon did say that the Y will be even bigger than the 10% size increase he said when it launched. He also alluded to it having other features that we will be impressed by that we don't know about yet. Not a direct quote obviously but from my memory that is what he said. So we might see some new tech/features in the Y which you might want to consider.
If you are going to be driving the 3 the most and without the kids, I would get the 3. If you are going to keep your Acura SUV parked cause you love driving the 3 so much, thereby ending up driving with the kids much more, then I think I would lean towards the Y for function. But again, I don't dig the looks so I'd have to have a lot of "function" needs to get me over the looks of the Y and to give up the zippy handling of the 3. Then again, I am kind of a jerk, so I would probably take the Acura to kids functions where it might be crowded school parking lots and cramped door banging soccer field parking lots. And then when I am on my own, drive the sweet ride lol.
I don't think my too much coffee rambling helped you at all. But hey, at least you are in a good spot being fortunate enough to afford either. Honestly I don't think you can go wrong with the 3 or the Y.