I take lunch with me to work everyday, but don't have access to a way re-heat anything and this bowl works fabulously. I pack my lunch at about 6am and at 12pm, when I come to eat it, it's still warm. It's also the perfect size.
At times the lid can be a little difficult to open because it is a wide lidded screw top, but I've never NOT been able to open it. 
I highly recommend this bowl.