Though brands like Tiger is the better ones. It's really expensive. So I bought Endo (5L for $99 and free 1.5L one which is on offer months ago at Takashimaya). It's been working well with soup and other dishes. There are also other mid-range brands thermal pots sold at Takashimaya, John Little, etc. I think will work the same.
There are 3 in the family. The 5L is a little big but workable. The 1.5L works well with porridge for my toddler. Like when I cook soup around 12pm, by 6pm it is still piping hot for the 5L. The 1.5L is a little less efficient due to its size. So endo is still not bad.
Just need to be careful while washing the inner pot. If the pot gets dented, the thermal pot won't work so well.
Hope this helps.