In my home we have all of the afore mentioned, because I believe this adds interest to a home, master suite has a huge tray ceiling in mbr.. and the baths have flat ceilings,kit. vaulted, media rm vaulted, guest suite has vaulted, while great rm. has cathedral, so simply go with what you like, and enjoy it! have seen some model homes that now have double, even triple trays, stepped up so to speak, and some homes have 10' flat all over..

I've had all in past master bedrooms and I prefer the simple tray ceiling. When you want to change your paint color, having a high vaulted or cathedral ceiling is a pain.

I think a tray ceiling makes more sense than a cathedral in your MBR because it has well-defined boundaries. If you do a cathedral, what happens at the sitting room, the new entryway/stair area and hall to closets and bath could all be tricky transitions. I have seen these transitions handled well, but more often I have seen them handled awkwardly. A tray avoids this because it is a well-defined detail. I don't think they are a fad, I have seen them in houses that are 50+ years old.

In addition to other comments above, you'd need to ensure the radically revised roof line required to install a cathedral ceiling on the second level of a home would blend in well with the rest of the house's roof lines. I think that would be a difficult look to pull off.

I have a 2-story shed ceiling in my LR, and it's very much a key architectural feature of the house -- especially the roof line. I love everything about it. But I have no doubt it would be a disappointment as a second-story feature.

Your challenge with a pop-up roof (I'm guessing that's what you're doing) is to ensure your add-on merges well with the rest of your house's roof design, so it looks as if it were initially designed that way, rather than an addition. So often we get so excited about the interior space, we forget about the external lines.

Have fun with your remodel!

How about a coved ceiling?

What is a cove ceiling? I did a search and could not find a good description. Do you have any pictures?
Thanks!