I'm not a fan. Last time we moved on the wish list was two bathrooms, neither of which needed to be accessed from a bedroom. So hard to find. Almost all second bathrooms are an en suite. Finally found a house that fits the bill.
The main reason for not being keen on en suites is the fact that i wanted the bathrooms accessible to both kids and visitors. I don't want anyone tramping through my bedroom to use the shower because someone else is having a bath in the other bathroom.
Also agree they are often too small for comfort or make the bedroom too small. I like plenty of space for lounging and getting ready. Plus if one partner uses the toilet at night the flush might be disturbing. Nor do I want shower damp pervading into the bedroom.
Some people love them and fair enough. Given the amount of houses I have seen with them I am probably in the minority.