I've read many of the reviews here on Amazon and since there were quite a few opposing opinions, I decided to try one for myself. First of all, I've seen many negative comments regarding the BOGO offer. Yes, I feel the shipping is a tad expensive but if you try to find these bags for anything less than $19.99 each, you'll be hard pressed. Trust me, I've looked. That means even if you were to purchase 2 of these from Amazon along with their free shipping, you will still be paying close to $40. Through the BOGO, I paid somewhere around $32 and change for 2, still a savings of $8. As for how the bags performed let me preface this by saying that I have a Prius which is rated by Toyota to get 50MPG. I've owned this car for 8 months now and so far my best average MPG has been 47. Close but no 50... I would say the 10 hours claimed by the manufacturers of Packit were gained in ideal testing conditions as was I'm sure the case for Toyota and the Prius. You have to consider this item for what it is - an insulated lunch bag with integrated cooling packs. I've used these bag for roughly 5 months now in many different situations, including our kids school lunches, my work lunches, beach outings and different sporting events. What I can say is that I love the convenience factor of not having to worry about separate gel packs and that the bags do what they say for average everyday use. I believe the average person (including myself) tends to pack a lunch in the morning with the intent to eat it 4-5 hours later. If you are in this group, your food will definitely be cold when it is time to eat. If your time frame is towards the 8-10 hour mark, this may not be the best solution as it is close to the upper performance limits of the bag. Take this review for what it's worth as I have not used any scientific methods in testing but instead put it through normal everyday use.
