Well, cooked the prime rib yesterday and took this bad boy out for the initial trial. A bit of a learning curve with it as some of the instructions are on the vague sign. When you insert the thermometer and go through the cook prep on the app (it guides you through the type of protein (pork, beef, chicken, etc and then through the various cuts), it gives you two temps, the internal of the meat and the ambient outside temp of the environment. It also says "estimating cook time". Got the oven pre-heated and put the roast in. The ambient temp went up quickly, but always stayed below what the temp the oven was set at, which concerned me that our oven might not be working right. Searched the site and it said that it give the accurate temp at the location of the probe sticking out from the meat and that non-convection type ovens have 'cold spots' in them and that it shouldn't be too concerning.
It took a fair amount of time for the estimated cooking time to actually generate a number. The interior of the meat started at 44° (I took the roast from the fridge about 2 hours prior to cooking to help bring it up in temp to make it cook better/more evenly as it was an almost 6 lb roast) and it didn't generate an estimated time for about 30 to 40 minutes after the roast was in the over and the interior temp of the roast was in the mid 50's range. The estimated time is always adjusting which was good because the first time it generated seemed waaaaaaaaay too long. But it adjusted itself based on the interior temp of the roast. You can set a "5 minute warning" where the app will let you know that you are about 5 minutes away from pulling the roast from the oven. We were going for medium rare which is an interior temp of about 135° and the app had me pull the roast at about 125° and then gave me a resting time. That time will also fluctuate based on the interior temp of the roast. took between 15 and 20 minutes of rest time for the temp to reach 135° and we were ready to dig in.
Cut into the roast and even the end cut was still on the pink-ish side which is hard to achieve because obviously the ends get more heat for a longer amount of time. The farther we cut into it, it was pretty close to a perfect medium rare. Maybe could have cut into it closer to 130° as I like my meat a lot closer to rare than medium rare, but I have to say, for my first go around with it, I'm pretty impressed with it. Took almost all the guesswork out of how long to cook the roast. I have a pork roast in the fridge for next weekend and will be trying it out again on that one and see how it goes, but so far, I really like it.