The only problem with both MS castles is that the outside is the biggest part. The inside of both is quite small. But, obviously, the more expensive one is better. If I were you, I would save up to buy a house from the crown shop with gold.Hope this helped! -Madison Silverblade, level 45 Pyromancer
Well if you want my opinion, I think the one house your going to stick with the longest. Some people that have memberships actually have enough gold to buy two houses at one time, but if your not your really tied. If you buy the small house and you're not happy with it whats the point, but it's not good to spend too much gold either! Big house it is!
The Imperial Palace (larger one) has lots of space inside and outside. It's beautiful from my perspective and is so calm and peaceful. Get the Imperial palace. The other MooShu house is so small.
If you want to garden with a large number of plants you need the large castle. The small one only has room for 50 items outside - 24 plots, 24 plants and a gnome or two.
It also depends on what you want to do with the houses. For me I'm getting the smaller sized Mooshu house simply because I don't have that many items to decorate it with. I also do not garden so I don't need the plot space. The small sized house is really nice, and easily workable with the amount of space.
I bought the Imperial Palace today and I think it has lots of space and is very beautiful. The Tranquil Cottage is too small so I would buy the bigger one.
I like my small MooShu house, it's my second home and I didn't want to have all those rooms to decorate. I love decorating the exterior most and it's a beautiful garden for my dragons to fly around and play in. Plus I love the little underground room. It was the perfect choice for me.
small has a limit of 50 items making it much to small to really do any outside decor. i am going to set up the portals in the lower chamber as a way station to get between houses fast
well i hope i got the answer. :D 
