While I like these self contained MVHR systems for single rooms, I wonder if they're good for a bathroom, where the overriding purpose is to extract humid air.
IMHO, it is a good idea to consider the whole house requirements, even when installing/replacing a single room vent.
I have a humidity sensitive constant trickle vent in my office, and further ones installed in our en-suites. In my case, I live in a long bungalow and wanted to have air pulled into the extremities from inside the house. If I were to install one of these, then I wouldn't get that air movement.
I have 5 of these in the house
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And they do a great job in controlling the humidity/air circulation. I think you can now get ones that communicate with each other and have one side of the house sucking and one blowing.
What I've also learnt is that most of the (axial) fans installed in bathrooms that duct through the attic to a soffet vent are grossly under-powered, and are spec'ed for only a 1m pipe run. Putting a centrifugal in-line extractor like the one linked by SETFORLIFE above is a much better idea. I went down that rabbit-hole recently dealing with mould and lack of ventilation in the bungalow.