I have a AWD Model 3 and a 2017 i3. I prefer the Model 3 by leaps and bounds. The two aren't even in the same ballpark.
If you are a "software person" like me, it's obvious that Tesla runs circles around BMW in all aspects of software: UI design, reliability, updates (or complete lack thereof!), map data, voice control, etc. Even the phone-as-key has worked flawlessly with my iPhone X.
Somehow the Tesla has double the power and range, AWD, is heavier, has normal size tires (that are stocked locally just about everywhere!), yet comes in at about the same EPA efficiency ratings. Tesla's powertrain is absolutely world class. BMW is a bit behind here in electric motors and the efficiency of their powertrain electronics. The CFRP is really cool, but if it's not more efficient, what's the point? The skinny tires are just a pain all around and don't seem to be better in any way at all.
My Tesla came in at $46k with a bunch of options on it--Somehow less than the sticker on my i3!
A few things I like better about the i3:
* Dent-resistant and rust-proof plastic panels. But I would miss that even if I went to another BMW model. I wish all cars had plastic body panels!
* Service experience. Tesla still has teething issues with service times and part availability. Thankfully it's not an ICE, so I expect my service appointments to be very few and far between.
* Build quality consistency. You have to be more careful looking for issues when taking delivery of a Telsa than a BMW.