Dryland (Anita's Artspace & Anita Witt Photography), makes excellent use of space to allow complex designs to rez.
The problem faced by all SL designers is that space contains potential computing space, and objects and people use potential computing space. There are strict crazy limits on everything. The typical fix is to cut corners, to use texture images rather than build 3-D structures is common, or to reuse the same item again and again reducing computation. But these makes for objects that look flat.
Dryland does it much better, fewer opens per unit space but rendered in wonderful detail. And it also understands the need for space to have meaning. Dryland presents a myth of a dried up river bed populated by gypsies to make it amazing large space with few objects make sense.