The MPO has some features that most people might not even notice but are extremely useful to people like myself. One difference I noticed between the MPO Craig used and my newer MPO is that the handle on the front has changed quite a bit. I don't know how well the handle on the original MPO worked, but the current handle design is great. It doesn't get hot at all. That's pretty amazing, considering how hot other parts of the MPO get, and particularly considering how much thermal mass the MPO holds.
But one thing that makes it infinitely easier for me to use the MPO is the side handles. This has nothing to do with heat (and I wouldn't want to carry the MPO when it's hot, anyway). The reason the side handles are so important to me is because I need to be able to carry the MPO with one hand, and the side handles make it possible for me to do that. Considering I can barely walk, I pretty much always need to have at least one free hand when I'm on my feet. That way I can grab things to catch myself if I lose my balance. And if I fall, I can brace the fall at least a little bit. Conversely, when I have to use both hands to carry something, I risk getting seriously injured; both from the fall and from landing under whatever I'm carrying.
I can carry the MPO with one hand. Because of that, my chances of getting hurt are infinitely less than if I had to use both hands to carry it. Additionally, I can leave the top stone in the MPO while carrying it, without having to worry that the top stone may fall out. All of this means I can easily transport the MPO in and out of the house. I can even use my cane while carrying the MPO. Ease of transport is not an issue to most people, but it's a huge issue to me and people like me, and the MPO's design makes it easy.