I have one of those lowerish wide enamelled cast iron braisiers... Staub 28 cm... this guy:
I think those and saute pans are probably pretty interchangable, although admittedly I never had a saute pans. My observations so far:
-It became my go to pan for fancier rice dishes, risotto, pilav, paella, etc...it does them awesome.
-I'd take this over a small cast iron since it has way more surface area to brown stuff.
-Similarly, because of the lower walls its a lot easier to stir.
-Also great for braising (duh), stews where you dont need the volume of a big tall cast iron.
-This model goes in the oven easy since it doesn't have a long ass handle.
-They sell these without the lid too. Get the version with the lid, I found it useful.
-Enamel is better for just leaving the food in for another day vs stainless.
-It's not a replacement for a big Dutch oven, but might be for a smaller one. Great to have alongside a big one. How much you use it probably depends on whether you already have a saute pan; I think they fill similar roles.
Do you need one? Probably not. You could probably do everything you do in one of these in a big frypan (for example a 32). Yet I found myself using it quite a lot and generally liking it. Definitly not a waste of money.
These models tend to go on sale at Amazon prime and black friday sales.