I just tested out the new oob google maps terrain data source, and it appears to be a jump to the same quality level as before, nice job!
The downside though is that you're limited to a relatively small area for the higher quality terrain. The larger your sample, the less detailed the terrain data becomes. This is a problem on bigger site models because unlike what we had previously with google inside of Sketchup, there doesn't appear to be a way to tile other areas around the base location and gradually build up your site in detail (rather than just taking one giant terrain area all at once that's very low quality).
If there was a way to bump up the detail level so that larger areas didn't automatically default to a 20x20 grid (which would be the easiest solution) that would be amazing. Allowing us to manually select other areas around the base location would also work though (like it is now with the 'add more imagery' function), it's just more tedious.
I couldn't seem to get the new create google map texture feature to work, but it seems like a promising new feature if we could get higher resolution areas than just 640x640.
Here's an example of the detail level at various scales (with the new Sketchup terrain source for reference). The first is a 200m x 200m area which you can see is much higher quality than what we have now, while the second is 1000m x 1000m. You can see how the detail level scales proportionally to the point that it's actually lower quality than the SRTM data.