I feel its easier to just look at the charts here -
Comparing the EVO, the EVO Plus, and the 970 Pro, I would say that the overall best value is the Samsung 970 EVO. The differences between the EVO and the EVO Plus are negligible for the average user. Of course, since the price difference is so small, the EVO Plus is a great choice if you are looking for higher sustained writing speeds. The Samsung 970 EVO Plus, specification wise, is the superior SSD of all three.
There isn't a very big difference in both price and performance between Evo & Plus, I would get a plus (wait, I have a plus)
The Pro is better writes but almost double price. Not really worth it for average users
970PRO is meant for high reliability and durability. You’re paying extra for enterprise level drive. Of all Samsung SSDs, the PRO designation means that it is designed for the lowest failure rate possible. Price doesn’t always mean you’re paying for speed.
1TB EVO Plus is rated at 600 TBW and 1TB PRO is double that at 1200 TBW so it will live way longer before it fails. I’ve seen drives rated at 300TBW fail after 3 years.
Pro can also write more before they run out of turbowrite cache. They made for server use. Not regular PC use (though I know someone with a Pro in their gaming PC). IN many of the tests the Evo Plus was just behind the Pro and that isn't bad for almost half the price.
It makes sense to pay $20 more for an Evo Plus for the added speed.