Steam really does work, but it depends a lot on how you use it and what kind of dirt you're dealing with. It's not magic that removes everything - if you have deep mold that's eaten into the grout, even steam won't completely save it. But for daily maintenance and getting rid of bacteria, stubborn dirt on tiles, and that sticky film that builds up in the bathroom, it's definitely effective. The heat actually kills the stuff, it doesn't just move it around like regular detergent does.
At my place, here's what happened: I was spending money on chemical products every week and the mold would come back right away in the corners anyway. After a few months with the steam cleaner, I noticed everything stays clean longer, and at least I don't have to spray bleach every day (which stinks and I hate it). The downside is that steam gets everything wet - if you don't have good ventilation in your bathroom, you're basically creating more humidity and making the problem worse. Plus the cheaper ones have tiny tanks and you have to refill them constantly.
My advice? Try an entry-level model before you drop 200 euros on one. A lot of retailers will let you test it for a few days, or look at the 80-100 euro models to see if you'd actually use it. If your bathroom tends to be humid, make sure the grout is sealed properly first, otherwise the steam gets in and creates problems down the line.