When it comes down to it, I value uniqueness and/or versatility over size, but wouldn't be unhappy about a big world either, especially since we haven't had one with 20+ lots since San Myshuno. I also agree with everyone saying that it shouldn't come with any unchangeable decorative houses in the background, which Newcrest unfortunately has in spades, but let us do with it whatever we want.
We currently have one world like that, and it's Forgotten Hollow, with only a few premade houses that can be changed or replaced, and nothing in the background or the surrounding area dictating how or what you're supposed to build (expect the graveyard surrounding Vlad's mansion and perhaps the general gloominess). Imagine that, but bigger and more generic (atmopshere-wise), with more than one neighbourhood and a mixture of big and small lots. I don't think anyone would say no to that.