Huge Speed difference between Samsung 950 Pro vs Samsung SM951, which should I buy?

Hi I noticed that his graphs (on the top there is a graph with an expanding green bar) showed how long it was taking for the data to be transferred. The 951 took 4 minutes 34 seconds to transfer 205GB of data and the 950 took 6 minute 5 seconds which said to me that the 950 was reading at a very much slower rate ( a good 1/3rd longer time). So that made me wonder if the 950 is inferior somehow but it is confusing as so many people seem to like it.
I have looked at your link carefully and I noticed, apart from the sentimental scores, that they do seem like a mixed bag but the 951 does seem to have greatly faster scores in reads and writes in the Average User and Peak Lab Bench scores. I see they both have identical Effective Speed scores so this has added to my confusion.
I think Puget Systems would have made sure to have both tests as reasonably close as possible so I doubt that they would have been using the computer with other things going on during the test so wouldn't the tests results mean that the 951 is superior overall because data is being read and written at a much faster rate?

ADDENDUM
I found Puget systems article about this test. It seems that the 950 Pro throttles quicker than the 951 due to its high temperatures.

They wrote this:

"Due to the fact that the Samsung 950 Pro throttles sooner than the SM951, we actually saw much lower sustained performance on the 950 Pro than we expected. To copy all 205GB worth of ISOs, the 950 Pro took about 365 seconds while the SM951 only took about 274 seconds. This translates to a sustained file copy performance of about 562 MB/s for the 950 Pro and about 748 MB/s for the SM951. In other words, while the Samsung 950 Pro does have lower temperatures than the SM951, it achieves this by being much more aggressive in it's throttling.

In our opinion, we actually prefer the earlier throttling on the 950 Pro. 98 °C may still be extremely hot, but it is much better than 111 °C. In fact, while Samsung even mentions throttling on the overview page for the 950 Pro:

The 950 PRO also features Dynamic Thermal Throttling Protection technology, which controls the temperature of the device to reduce overheating and maintain a high level of sustained performance.

Samsung's overview page for the 950 Pro makes it clear that this drive is designed to throttle when the drive gets hot so the high temperature on the controller shouldn't impact the longevity of the drive. However, even if you are willing to trust that Samsung has addressed the high temperatures appropriately, you still will see a drop in performance if this drive gets too hot. And since that happens after only about a minute of sustained file transfer, it is likely that most users will run into this throttling at some point.

If you want a high performance drive that is able to achieve the advertised performance over prolonged periods of time, we would highly recommend using this drive in combination with a PCI-E adapter that includes a heatsink (we use this adapter ourselves) or otherwise affix a heatsink to the controller chip to help dissipate the heat."
https://www.pugetsystems.com/labs/articles/Product-Review-Samsung-950-Pro-512GB-M-2-Drive-725/

So the built in throttling is the cause of the slower performance. I do not know what to make of this. Anyone have any ideas?