Used Stekkies over about six weeks searching for a rental in Leiden as an incoming student. The core value is real: it pulls listings from Pararius, Funda, Huurwoningen and various direct agency sites into one alert feed, which saved a lot of manual checking across platforms. Do note that it doesn't aggregate Kamernet (to my knowledge). Some listings from paid source sites show up locked unless you subscribe to that platform directly.

Otherwise the alert speed and filtering were solid, and it was the backbone of how I found and tracked properties day to day.