When my GPS mouse arrives, I'm going to try GPSS first because it is free.
Biggest problem is that the maps are Bitmap, rather than in vector form, so they won't scale very well.
You are right, the website is very messy. They could do with a serious rebuild to improve their image and make it easier to navigate. And yes the links to lots of maps is extemely useful whileyou get used to using GPS.