I think designing a map with complicated sequences, taking into account the latency of others, is much more challenging that being given a blank slate. Limitations are what make halflife so fun to map for, I just love to try and break them in every way I can.
Overlord is very complicated (I can barely understand it myself now), but fun for people with all kinds of connections. The netcode is suprisingly resiliant, even when you are trying to control 14 people parachuting, each looking at themselves through 14 cameras!