All the new features for RC 4 are indeed pretty nice additions so this isn't to take anything away from the updates. But with all that time and effort put into the new workflow features, it seems crazy to find that some of the most basic problems with the RC libraries are still there so many years later!
1. Roads/Streets still have no way to generate intersections! It's like the most basic aspect of laying down streets. Anytime I use RC for generating roads I immediately run into this problem and then end up spending so much time trying to get an intersection set up any time saved using RC is erased. Seriously, do you ever see roads go off into the distance and not be crossed by multiple intersections?
2. Sidewalks run into this exact problem as well. Most city walks, and especially walks within a building's grounds, don't have a 10' radius curve when you get to a corner. Most often the walk ends at a 90 degree juncture or in a very tight radius. Now maybe the new version will address this with the capping feature, but again, having walks being able to have intersection-like details really seems like a must have rather than a nice to have feature.
3. Bitmaps: This is a slightly less problematic issue but what about the actual materials assigned those same sidewalks? I have almost never seen anything like the way you have them laid out. It's as if someone hand placed these small cobblestone like tiles down the entire walkway? What place does this? Certainly no city I know of. Shouldn't the defaults just be simple like A: US Standard poured cement guidelines, or B: European Standard poured cement guidelines?
In the US the typical spec. says that poured cement sections be not less than 3' and no more than 12' long, by 4-5' wide. So you pick maybe the standard concrete section to be 4' wide by 6' long. This would cover 90% of your typical sidewalks, which you would think would be the default parameter. But instead the choices you get only really work for what are decidedly very rare occasions when you want ultra fancy brick-lined walks with bike lane added in. Yes- I know you can change these in one's libraries and all of that, but wouldn't it make more sense to actually have them built in?
4. Bitmap resolution: They just need to be a lot larger. If you render out either a very large image or just happen to have the camera close up, a lot of the bitmaps start to fall apart. and in the case of the roads, probably should be procedural so you can't see repeats. Take the rc_asphalt02-4m-dif map for roads: 2400 x 600. That might sound good until you realize it spans a very short length of road and it becomes obvious that's a repeat as soon as you see it at length. 10 years ago that might be OK, but today you'd assume to have bitmaps double or triple that size. This issue applies to many of the other maps as well.
Again: I appreciate RC for what it is, and in many cases it's saved my dozens of hours on projects; so that's not the problem. But right now it's more of a Good product, whereas with a few updates and logical ways of implementing defaults it could be really Great.