It depends on your end game. My wedding and event clients love the kitche-ness of the whole thing.The Sofort is the Fuji Instax Classic Neo 90, for all intends and purposes. It's just packaged up differently, and there is one major difference: The lens ring serves for zone focusing whereas you have to use the menu with the Neo 90. Technically and in terms of IQs, they're the same camera. You pay double for the red dot and an admittedly much more clever use of one single feature.
But it's indeed quite rare to see the Neo 90 in the wild - the Instax Mini 7/8/9 series are much more frequent, and they're actually okay cameras, considering how cheap they are. But apart from the novelty value of just snapping away, they're very limited tools (which can be intriguing). They have the same lens as the Neo 90, btw. - a dim two-lens affair with a 31mm equivalent at f/12.7, nothing to write home about. Surprisingly, the cheap cameras are fully manual - you have to set the aperture for solid results, and the flash always fires (you can switch it off on the Neo 90!). An interesting alternative to the cheapest Fuji cameras is the original Lomo'Instant - it's a more old-fashioned, but also more versatile camera. Results are ... adequate, at best. Softer than the Fujis, but quite dramatic, more often than not (due to a huge amount of vignetting - the Lomography signature). And you can use screw-in filters, including NDs for daylight shooting.
I own a couple of instant cameras because I find them very interesting creative tools - because of their limitations and idiosyncrasies. I'm fascinated by instant photography because essentially, you have to get it right, or you have to throw it away. Lomography offers a couple of very interesting cameras, but the Neo 90 is still your best bet for Instax Mini if you need reliability. The best images come from the Lomo'Instant Glass that sports a surprisingly sharp and true 21mm equivalent lens for exciting perspectives - but its metering and shutter are inferior to Fuji's offerings, so YMMV (I always carry a two-stop ND filter to be able to shoot in daylight). The other very interesting provider is MiNT - but their cameras are way more expensive. Yet the TL70 2.0 and still limited RF70 are top of the pack in terms of features and results (the TL70 TLR uses Instax Mini, the RF70 rangefinder uses Instax Wide).
What I don't get is image printing on instant film, I'm sorry to say. It's a hideously expensive way to get mediocre prints. It has its appeal, and it sure is a nice conversation starter as well as a way to show your appreciation for your subjects on the go by offering them one of those tiny images. But Canon's SELPHY printers are way better, not much bigger and offer a clearly cheaper print price. I don't have any experience with other Zink paper printers, though.
I provide a service where I give them 20 instax prints on scene from the reception for $100-200, depending on the instax size. It is a big hit. People are always walking around the table to see what new images are placed there.
It also gives those that didn't usually interact a common subject for discussion.
I've provided process both ways, from lofi cameras directly as well as printing from the Fuji app from my Nikon DSLRs.
As a photographer or straight documentation, it makes little economic sense. However, from a cultural perspective, it has some broad appeal in this digital age, which is great.