I've got this one too and do use it on average once a week.
I had a cheap aldi one before which I used a fair bit too but when it broke I replaced it. I've bought so many gadgets over the years but the only two I regularly use are this soup maker and my slow cooker.
What I like about it over a pan and stick blender is that you just chuck everything in at the same time and just leave it for 20 minutes. I've found that as long as I include onions, that gia garlic paste, stock, seasoning, sometimes a bit of tomato puree then whatever veg I use it turns out consistently good. My favourite is broccoli and stilton, so I add stilton and creme fraiche at the end and then blend again. In fact cheese makes all the soups better.
My daughter uses it too. She's 15 and should really be able to cook better than she can but she's doing her gcses/would rather wait for me to produce something so the soup maker is good for this too.
I'm not really a great cook though, so you might prefer your own soups? For example, if you'd normally roast your veg first then it's probably not going to be better than that. But for basic soups such as veg, brocoli and stilton, carrot and coriander, spicy parsnip etc then it's great.
Also, it's good for less food waste. I keep the "core" bits from cauliflower and broccoli for example and use it now for soup whereas before I'd have just thrown it away. You can use the "woody" bits from kale and greens too. I just put these in the "soup box" now in the fridge.