I think the subscription only gives access to online maps - so you can view online, and print off maps to your hearts content.. I fail to see how this is better than just looking at bing maps..
No good for Garmins I'm afraid, as you do not actually own the files, and even if you did, and you put them on a mini SD card, they would probably be the wrong file types..
Keep checking ebay, I got my map SD card off there for a few quid