The manuals could be a bit simpler, a lot of stuff I've learned through trial and error. However, it is quite easy once you get the hang of it. Timetabling buses can be quite complicated and fiddly, though - but the actual creation of the map is fine.
The only problem is when terraforming (i.e. sculpting the land). There is no automated feature to 'snap-to' the terrain to roads, so you will spend a lot of time carefully crafting the land getting it to match your roads (unless you make your map on a completely flat land lol)