We use ours multiple times per week. We had a slow cooker previously and replaced with an IP when it broke. From a financial perspective, I think the advantage is that while it's not instant, it is much more "instant" than the alternative options (stovetop, slow cooker) for batch & budget cooking, so it's easier to implement. It is also quite energy efficient, so can potentially shave a bit off your power bill if you switch certain tasks from stovetop/oven/slow cooker to instant pot.
The things I like most about it:
-requires less advance planning than a slow cooker
-requires less attention than the stovetop.
-Cooks more evenly than the pressure cooker
-more versatile
We use ours for a lot of basic stuff, like:
-rice
-lentils/beans
-making giant batches of seitan (a high protein vegan meat substitute made from wheat gluten, very cheap if you can find the gluten flour in bulk)
-any kind of soup
-any kind of curry
-tomato sauce
I have also recently started shifting making things like steamed vegetables, applesauce, and berry compote off the stovetop and into the instant pot.
Since it is not something I see mentioned a lot, I am going to give my basic recipe for seitan. This works best if you also have a food processor. The quantities below are the max my food processor can handle, I typically manage to squeeze three batches of this into my IP. Note that it is a bit of a pain to clean the food processor, so really is best to make multiple batches in one go so you only have to do one round of cleaning. We mix with veggies, legumes, and sauce/seasonings for easy packed lunches during the week.
-1.5 c hot water
-1 c. cooked beans or lentils (I've been using pinto lately)
-1/4 c. nutritional yeast
-2 cloves garlic
-seasonings: whatever sounds good to you, I like things like cumin/coriander/paprika/cayenne or fennel/sage or italian seasoning, onion powder, etc.
-1 tsp salt
-1.25 c vital wheat gluten. I find this for about $3/lb in bulk sections of health food type stores.
Directions:
Have InstantPot set up to steam (steam rack inserted and 1 c. water in the pot)
Blend together 1 c water, beans, nutritional yeast, garlic, seasonings and salt
Add remaining 1/2 c. water and 3/4 c. wheat gluten. Blend.
Add remaining 1/2 c. wheat gluten. Blend some more. You should have a wet/sticky dough.
Place dough on a piece of parchment paper and shape into a rough sausage. Roll paper around sausage and place in IP. Repeat 2-3x for a total of 3-4 sausages in the IP.
Pressure cook on high for 25 minutes and allow pressure to release naturally.