I have been casually playing with this a bit, but I don't have a subscription so I can't say how it works on the GPS itself. On Garmin's BirdsEye page the info implies you are only limited by the amount of memory. Really, I can't believe there was ever a technical reason for 100 tiles. I mean, DeLorme, OziExplorer, Magellan Triton all can use raster imagery without such a restrictive limit. I think it was done for marketing reasons.
I have only downloaded little areas so far on my computer. Once I selected an area and it reported I exceeded the limit (at 1GB). Elsewhere I've read that people were able to download 300MB before getting the warning. Just now I decided to try a larger download. Basecamp reported that my chosen area was 30 MB for the highest resolution data. It's a little confusing how this works; a dialog box came up very quickly saying the imagery was ready - no way I could have downloaded 30MB that fast! But what I had was very low res coverage of the entire area. Zooming in resulted in a mess.
Down at the bottom of the screen there's a tab that says "properties". A thin green progress bar appeared down there; took me awhile to notice it. But I see it is now slowly and steadily loading the full res image. If I go to the upper left corner and zoom all the way in, the full res data shows.
I don't think there's anything to prevent you from downloading overlapping areas until you have covered a huge area. But there is one interesting thing. When the BirdsEye download dialog box first appears, it says something like "Available space: 690 MB". I have 260GB free on my C: drive, so that's not it. It seems to be the amount of free space on my Oregon's internal memory.
I may be jumping to conclusions here, but that would imply I could load a really large amount of BirdsEye imagery. Others have reported that the imagery must be saved to internal memory, but you can later copy the files to the memory card. Whether or not Garmin has intentionally limited it to internal memory isn't clear. But if they have, then this is one argument for getting the "t models" since they have 4GB internal storage.
I'm looking forward to seeing more user reports. Several people indicated that their paid subscriptions aren't working, and Garmin is closed for the holidays here. I will wait for all the glitches to be ironed out before I subscribe.
