already have the roof box (Motion XL) ... we want MORE space!
I've just upgraded to the Y after 3 years with the 3.
Here's my plusses and negatives - it's just my opinion though
1. Getting in and out - Y is so much better, as someone who has bad knees it's great also don't need to use easy entry mode on the Y.
2. Driving position - when in the 3 you are down closer to the floor, the footwell seems shallow - in the Y my legs don't dangle per say but are at a much more comfortable position and the mild discomfort after a long drive at the back of my thigh has cleared up.
3. Rear view - whilst the 3 wasn't great the Y's rear view is TINY, thank god the cameras are good for rear view.
4. Ultrasonic sensors/Teslavision - yes it's been hashed out everywhere and I thought it wouldn't be so bad, gut going from a 3 with sensors to a Y without it's not great, AP tends not to hold the line on the road as well - that might just be me thinking it! Oh and after 24 hours of having the Y, very mild scrape against another car (badly parked) but I'd have known in the 3 as the scrape is in almost the exact position as one of the sensors.
5. Parcel shelf - whilst it's great to have (sorry early order Y people!!) it's ... just ... weird, it has folds to slow to move it out of the way but it just gets in the way and you have to hold it in the open position.
6. Heat pump/steering wheel heater - Going from the old school heater in the 3 (mine was pre facelift but with the new style frunk) to a heat pump and heated steering wheel (damn that gets hot) it's nice and doesn't seem to sap as much battery as the old one - but we'll see in the next few months!!
7. General range - I though it would be worse than my 3but it's pretty much even and frequently better than my 3, there may be factors (new cells/heatpump etc) to that but that's what I've seen.
All in all it's a mixed bag, yes I'm happy with the Y overall with some minor bugbears and I did love my 3.
Have a sit in it, get a longer test drive (if you can), try parking and if possible AP. Personally I'm happy I went for the Y - TBH it was what I wanted originally but at the time my lease was up only the 3 was available.