Heh, now I'm in a mood to talk RWG, Tiles, Parts.
With POIs folks kind of like memorable POIs. With Tiles, being memorable seems to contribute to a Flintstones/Bedrock feeling where you keep passing the same few background items again and again. For instance:
- The dogleg around the pond on rwg_tile_rural_straight
- The roundabout on rwg_tile_residential_intersection
- The road loop on rwg_tile_rural_countryresidential_cap
- The bridge on rwg_tile_downtown_interesection_02
- The tower on rwg_tile_downtown_straight
Parts offer an opportunity to disguise the dogleg/pond, the roundabout, and tower. Maybe the bridge too, but that might be an awkward fit.
In contrast, while I'll bet many people remember the road construction that can appear on rwg_tile_downtown_intersection, since it only appears 40% of the time, I'll bet those people don't always recognize the tile itself being repeated.
The human brain is really good at patterns so we're probably doomed never to have "enough" variety, but I think extensive use of Parts can mess with the brain for a bit longer.