Just do eet! $500 is a great price. The power is ok, I have heard the T5 has more to gain than my T6. But the drivability improvements, the AWD behavior, trans shifting, all sooo much better and totally worth it.
Before I bought my 2019 S60 T5 I test drove models with and without Polestar and noticed a difference. It's a personal decision for each individual, but to me it the Polestar was worth the extra cost, even at what the dealer charged (which was way more than $500).