You think that you would like something, until you get it, and then find it doesn't fit in with the way you live.
We got a conservatory about 12 years ago, I was desperate for one, and we had one built only to discover we had no use for it. We've tried it as a dining room (preferred eating off trays from our laps in the living room), a kids playroom (they preferred their bedroom or annoying us in the living room), an additional living space (we prefer to sit together and watch the same TV), a laundry room (went mouldy with tumble dryer in there), an office (had to have 2 heaters on full to work in there) and a dumping ground (this was the biggest success).
Anyway, if we ever move I would like a downstairs toilet (or room to build one), a second reception room which I'd turn into an office, and a kitchen big enough to get a table and chairs in. I'm not bothered about an en-suit or a big garden.
I also would not like open plan, I never even thought of the noise issue - my bugbear is the cold. When we have the door between living room and kitchen open it's freezing!
If we stay here, I'm waiting for the DS's to move out then turning the small box room into a walk in wardrobe, dressing room.