One tip from experience: red lentils can stick and burn onto the soup maker base, perhaps especially with tomatoey soup. I’ve learned to soak the lentils for a few hours before tipping them into the machine. My soup maker was out of action and in disgrace in the cupboard a copule of times for this! Other than I’ve enjoyed soup maker soup for lunch for years now. I’m definitely in the really love it group.
I used to make soup in a large saucepan on the hob but that was before I bought an Instant Pot which doubles as a pressure cooker or a slow cooker - It has been a game changer for soup making. Personally, I wouldn't bother spending on a soup maker, as someone else commented "just another gadget in the cupboard".