My in-laws have one. They rarely use it. We've used it for soups, mostly. That's about it really, as far as I can remember. Personally I wouldn't buy one but I guess it depends on your lifestyle and typical daily schedule.
I adore mine! I do really like fine purees, and once you use a Thermomix, even the punchiest conventional blenders fall flat. Also makes brilliant ice cream bases and curds. Just having one around opens up options. Quick infused oils and vinegars, spice blends, etc.