Initially had an Airflow Icon 30 which electrically died on me 2-3 years in, a common problem I later found reading through online reviews. Good noise level though and moved a lot of air (good CFM).
Replaced that with an Xpelair C4HTS "Simply Silent" fan. Not silent at all and I think I could have blown air out of the bathroom quicker. It developed a fault maybe 6 months in where after being triggered by the humidistat it wouldn't turn off, for hours, sometimes even ever! Until it was physically isolated/switched off from power.
That's when my story with the Vent Axia Svara begins, I read a few reviews and was sold on its apparent reliability, accuracy and easy of setup/config. And that's no lie ladies and gentlemen, it really is worth every penny. I only had to connect a live & neutral cable and we were away, the humidistat is so much more accurate, it comes on shortly after starting the shower and doesn't stay on for too long after. It's much quieter but still pushing 30l/s of air! It's such a relief to be able to control it all from a smartphone app rather than having to tinker with potentiometers and jumpers atop a step-ladder. It's the first "smart controlled" thing I have in my house and I don't regret it! I personally don't use the light sensor trigger or have the fan continuously running but it's super quiet in its low speed/power 10l/s state.
Highly recommend this, it's worth the extra money!