Is there a way to download the maemo mapper tiles (openstreet) to a PC first and then transfer to my N810? It would make it much quicker for me, as trying to d/l almost 1gb of maps through the N810 is taking forever.

Yes you can. Then transfer the file via USB cable or perhaps bluetooth like I do. If the file is installable, open it in file manager, click it and the installer will take over.

Maemo Mapper shows altitude in the GPS Details display. I downloaded the Google maps and use my N810 without Internet connection. I also installed a-GPS which requires a network connection only when you change your location more than about 180 miles. There are a number of map databases offered and some are much smaller than Google's.

As someone said before, yes, you can download the maps in advance. However even with the map data Maemo Mapper needs Internet connection to receive route instructions. This means that if you have downlaoded map data and route info and your route is blocked for whatever route, you cannot simply take anoter route and ask MM for new route. Similary, if you miss your exit on a highway, MM won't find a new route automatically. With MM you'll always need Internet connectivity to find a route. Finally, MM reads route instructions from downloaded XML-file using speech synthesis. Usually this means that route information is usually like "turn left to Foobar street and go 47 km" instead of "take second lane after 200 metres and turn left".

Personally I like MaemoMapper, but it's horrible memory hog. I've practically given up trying to use MM and Browser at the same time. I only need to scroll the map a bit and MM has consumed most of free RAM and likely some of swap as well. On the other hand using Maps draws more power.

If I needed GPS routing, I'd choose Maps over MaemoMapper. Personally I use both.

Is it possible to download finer detail instructions? I've been looking at data and it's not too costly nowadays (~£5/month unlimited); being able to use maemo-mapper as a decent routing tool would be useful, but as said above, it would need to be able to actively ask for route updates, and would also be nice to have higher detail routes.

Any thoughts?

As far as I can tell MaemoMapper simply reads out directions of a route point when you get close to it. If you can get istructions with finer detail I'm sure MM will happily use festalon or such to read out the instructions for you. :-)

The routes I've tried come in XML and as such are easily editable. If you want to experiment with MM and routes that's an easy way to start. In my opinnion however it would be better to forget speech synthesis and find a way to receive coded directions. What I mean is that it would be better to receive driving instructions in machine readable format instead of plain English. That way it would be much easier to use pre-recorded voice samples (e.g. borrow the samples from Maps). As you probably know, consumer-grade speech synthesis isn't very good.

About GPS altitude - you should be aware that altitude isn't accurate at all. The globe model in these consumer grade GPS receivers isn't good enough for that. As a minimum you will have to add a correction factor for your current area.

Or use a lookup from your lat/long using the shuttle radar mapping data to work out how high you should be perhaps

While experimenting with Maemo Mapper I noticed that the altitude reading varies in a 3 or 4 meter range which may be close enough for some uses. I've also seen slight movement indicated when standing still. This being my 1st GPS I don't know if this is common amongst other devices. Without documentation or prior experience with GPS devices this application can be confusing.

The GPS receiver uses a globe model? I am surprised by that as my N810 seems to get my attitude correct when I'm on an airplane when comparing to the inflight gps video.

Does GPS suffer from signal reflection? I notice that whenever I drive under a bridge my position is usually systematically offset.