IMPs are great in that you get tooth pick, matches, gum and toilet paper. Some of them have a chocolate bar. Good stuff.
But having tried freeze dried, I will not backpack heavy IMPs or MREs out on the trail ever again.
The only way to stuff three days worth of MREs in your pack is by field stripping. Then you are throwing half the stuff away.
With Mountain House all you are left with is the zip seal bag to pack out your garbage.
I ate a Mountain House dehydrated meal out snowshoeing this last weekend, chicken and rice. Tasted good, filled my belly.
As I sat in the sun on a rock with my JetBoil stove and waited the 2 minutes for the water to boil for the ration and to make myself a tea, I read the back of the packet. The best before date (note, not expiry date) was 2047.
In 2047 I would be 90 years of age, so the food likely has a later expiry date than I do.