Well.... I played a little with the blueprints feature. I was working with the gothic blueprints as, of the offerings, it would be the preferred style in my fantasy building (not so interested in real life). My feelings are:
Unless you sit there for a while and figure out what their intended arrangement is for the gothic blueprints, you're going to be spending a while simply rearranging windows, doors and - as a result of the first two - probably the contents of the rooms. If you do manage to determine their intended design, you and everyone else will wind up with the same floorplan. Blah.
I feel that there should have been different size rooms offered of the different styles. i.e. 2X3, 3X3, and a larger master bath in each style, a master bed and a guest bed in each style, etc. Also, there isn't a foyer, art room, nursery, kid's room, (etc) for each style. (I rather miss the gothic kids rooms from the Sims 2.) In fact, there is only one foyer that I could find - Contemporary. There is only one gym, too.
I can only hope that this lack of variety in the existing styles will be rectified with Seasons, as opposed to only adding new styles.
There is some decent decorating in each room. It's a little like having the demo rooms from the store on your computer. Though, I didn't see much - if any - store content used in the rooms, there are some nice recolors. The gothic rooms didn't make use of the Supernatural content, which would have been an excellent fit. (This is to be expected, I admit, since this was a between-expansions patch.) Dare I hope that they offer better planned blueprints of the expansions and store sets in the future?
Overall, they're nothing that I couldn't do for myself fairly easily. And, doing it myself, I would get precisely what I want instead of having to figure out exactly how to fit their ideas into my sim's home. Still, not bad to use to spark ideas or if you want only one or two of the rooms instead of an easy gothic insta-house.