Thanks for offering up some pointers Mr. Carver.
I've been mostly happy for about 6 years using GoogleMaps in this same way, and end up consuming all [free, no cost] 10 layers by the time I've partitioned off a longer multi-day trip route (with layers, often 1 layer for each day's route just to keep each day's ride looking simpler in my Android tablet GPS solution). I like that we can use Google-centric map icons for waypoints, create / import your own custom graphic icons, draw odd-shaped polygons, etc. too. After using so much, I've realized that there may be some interesting ways to use layers, and these can make your future mapping efforts quicker - wherever you find yourself selecting / drawing a number of the same types of points over and over again:
- layer for accommodation waypoints (I took a couple hours a year ago and decided to research & add a large series of hotels across most of western North America)
- layer for bike repair shop waypoints (could come in handy if someone in my ride groups suddenly needs a serious repair OR new rubber out far from home; I even copy & paste in their local phone numbers as a text property)
- layer for annual music festival waypoints (after discovering a kewl website where so many festivals/concerts are registered, I again took a couple hours to carefully locate them across most of western North America)
- layers for mountain passes, points of interest, dams, hot springs, etc - whatever your ride group could be interested in as you move over geography
- layers for a whole series of curvy road endpoints, which I use to form a "patchwork quilt" path on some interesting rides; I intentionally grouped these by range of distance from my home town, giving each group of those waypoints different GoogleMaps colours so they stand out better
This is why its easy to start "running out of layers" but overall, GoogleMaps really meets most of my needs. I too, discovered that GPS Visualizer site for conversion of my custom GoogleMap routes into .GPX files which are then fairly universally useful. Guess I should finally pony up and offer that site's Administrator a proper donation now(!).
Hope that extends some useful ideas for other GoogleMap users here too...