redsquash,
With pressure cooker you have to be "there" all the time. With thermo pot you are only in the kitchen for 10/15 mins. Thermo pot cooks in lower temp so preserves the flavour much better. You can think of it as a slow cooker but does not need electricity. The only energy it needs is the 10 mins or so on the stove at the begining ,to bring to boi evenly.
I have the 6litre Tiger brand. It continues to cook for hours not minutes.Yes you can over cook your veg in it it if you don't want them too soft but carrots, potatoes etc are OK.
For example to cook soup/broth with pork bones/ribs, carrots, potatoes, beetroot, peas, onion, I put all in the inner pot+water, bring to boil, put in salt, pepper to taste, skim the "dirty" froth etc , put lid on, wait for it to boil evenly for another minute or 2, then take it off the stove, into the outer pot.
That's it.
If i do this at night before bed I can have hot soup/casserole ready for me in the morning. If I cook in in the morning, after the initial 15 mins as I describe above, I can then put it in the car, go shopping for 5, 6 hrs and then drop by a friend's party in the afternoon/evening with my casserole still hot yummy ready to eat. This feature is unique.
Drawback is it does not cook "quickly" as the pressure cooker. And it is quite expensive, (in the high $200). I heard some cheaper brands may not keep the heat/cooking long / well as the Tiger.
Asian people particularly Chinese use this pot a lot coz the Chinese believe in the health benefit of drinking soup (they have so many different types of soup for different seasons, benefits etc).