I was actually really impressed by the Polestar 2, I ordered one then canceled in favor of the M3P. I still think the Polestar 2 is an overall better car, but the Model 3 is a better EV, if that makes any sense. My thoughts on this may not be popular here, but I'm going to say it like it I see it.
I did two test drives each of Polestar 2 (fully loaded Performance+Pilot+Plus) and Model 3 (first M3LR then M3P), and got to put each car through its paces. Here's my "short" form comparison...
Model 3 pros:
1) [USA] supercharger network: Coverage. There's a notable gap in public DC fast charging in an area I drive around regularly.
2) [USA] supercharger network: Number of plugs per site. Lots of big supercharger sites nowadays, whereas EA and EVGo are like 1 to 5 plugs per site. If a big supercharger site is full, there will be turnover soon, but if a tiny EA or EVGo site is full you might be waiting a while...or wasting energy driving around trying to get lucky at a different tiny site. Right now those EA and EVGo sites may be mostly empty, but the Mach-E, ID.4, etc seem to be selling pretty well, I think that's going to change quick.
2) [USA] supercharger network: Charging UX. With a supercharger, you just show up and plug in. The stories I've read of trying to pay/active public DC chargers sound horrible. I've no interest in fiddling with my phone, digging out lost RFID cards from under my seat, etc. There is a public charging standard called Plug & Charge that should give Tesla-style charging UX, but Polestar hasn't promised to support it. (And I did pester their sales reps about it multiple times.)
3) Range. Real world difference is less than EPA difference, from what I've seen, but it's still real, Model 3 is more efficient and has usefully more highway range (where it matters most usually).
4) Visibility. Model 3 has tall glass and low beltline by modern car standards. I like this. Whereas Polestar 2 is a bit bunker-feeling.
5) Model 3 center infotainment display is much bigger and sharper.
6) M3P accelerates quicker from a dig / low speeds. (At highway speeds the Polestar 2, M3LR, and M3P all feel roughly comparable to me. Basically Polestar 2 felt approximately like M3LR or MYLR in terms of acceleration.)
7) I think Tesla is solidly past the risky-new-car-company stage now. They're going to be here supporting their cars for many years to come, and the USA is home base. Whereas Polestar as an independent-ish car company is very new. Will they succeed? Will they succeed *in the USA*? Will they be able to support the China-made Polestar 2 in the face of geopolitical issues? Polestar's next car will be USA-made and USA-focused, but at the moment, their supply+manufacturing chain looks riskier to me than Tesla's for long-term support of the car.
8) The Model 3's super quick steering ratio (10:1 ?) is fun. (But the Polestar 2 Performance has quicker steering reactions, even with its slower steering ratio.)
9) Tesla has a much stronger set of EV features. Leave climate on / camp / dog modes, scheduled charging builtin to the car, supercharging is plug-n-play, etc. Polestar got some things right, e.g. starting the car is same as in a Tesla (press brake + shift into D/R), so they may catch up via software updates but for now Tesla is still ahead in this.
Polestar 2 pros, based on testing a fully loaded Performance+Pilot+Plus version:
1) It's a hatchback/fastback. Cargo space is no bigger than Model 3, maybe even smaller because Polestar 2 is shorter, but the hatchback opening is more useful than a trunk. (Yes Model Y has a hatch and way more space than a Polestar 2, but the Y drives like *sugar* in comparison - sorry Y owners.)
2) Polestar 2 Performance handling (with stock Öhlins dampers) is night-and-day better than M3P or M3LR. I can't overstate how much better the Polestar handled for twisty roads, especially uneven back roads. M3P and M3LR are a sloppy mess in comparison. Even on smooth road it's much better, quicker to react, more stable, etc.
3) Polestar 2 Performance ride quality was also much better than Model 3 (LR or P). It was definitely firm and sporty, but smaller bumps were completely smoother over, and large bumps were felt but never harsh. The ride/handling balance was in a whole different league than Model 3.
4) Polestar 2's lift-off regen (in max setting) is much sharper and quicker-reacting than any Tesla I've driven, where the regen always feels a little slow and mushy to react. I liked this very much.
5) As a tall-ish person, I find Polestar 2 back seat a lot more comfortable than Model 3. Yes there's less legroom, but the seat is much higher off the floor, Model 3 back seat is so low it's very uncomfortable. Polestar 2 has just enough legroom that I could plausibly sit behind myself for a long drive.
6) The Polestar 2 front seats seemed to hold me better in turns than Model 3. Not sure if better bolstering or just gripper material.
7) I think Android Automotive has potential to become better infotainment than Tesla. Lots of automakers are getting onboard, I expect the app ecosystem will grow and eclipse Tesla's functionality soon, especially for streaming apps.
8) Polestar 2 has all the regular driver's controls. There is a wiper stalk/knob, no need for touchscreen to control wiper settings. And the turn signal stalk works the normal way, where I can feel what it's set to. I hate how the Model 3/Y stalk always returns to center. Hopefully I'll get used to it...
10) Polestar 2 has a driver's display.
11) Polestar 2 ACC on my test drive was smoother than my M3P's TACC. Note, I've only used it once on each car, so this is very tentative comparison. I have used TACC many times on Model S loaners over the years, and I actually feel like Tesla TACC has regressed, my M3P seems worse at it than those older Model S.
12) Polestar 2 Performance package comes with forged wheels. And tires with some actual sidewall (not too much). And the tire width looked matched appropriately for the wheels, not overly stretched like the 2021 M3P stock tires.
13) I think Polestar 2 highway wind noise was a little lower than Model 3. (Definitely lower than Model Y.)
I really like my M3P, and I'll be addressing its suspension flaws via Redwood Öhlins coilovers. But I do think Tesla needs to step up some aspects of their cars before their range+charging advantage becomes less of a thing.