Yeah, the purpose of the instant read is to find the "thermal center" which is to say, you want to find the coldest part of the meat. And the only way to do that is to take multiple reads. The strategy is to insert the very tip of the device a little above where you believe the center is located. Take a reading. Then push it just a bit further, take a reading. This reading should be a bit colder. Then push it in a bit further. And by this time, you will likely be at the cold spot or past it. Take a reading. If it's still reading lower, you have to push it in again. Take a reading. By this time it should be hotter than the previous spot, so back it up to confirm the cold spot. And that's your internal temp. In this example you might take five different reads to find the cold spot.
If you have a 1-sec read device, all this would take about 5 secs.
If you have a 8-sec read device, this same procedure would take about 40 secs.
Hence, the advantage of a super-fast read.
Good luck