Navigating gadget

I got a Navman iCN 510 for my birthday, and having just been to Canberra and back, here are my impressions (in no particular order):

Cons

There's no way to enter GPS coordinates. It shows them on the map, so you can hunt for them that way, but it'd be much more convenient to type them in numerically.

Similarly, it doesn't allow entry of house numbers, even though it knows about them. You get to select a number range, and then you can again hunt for them on the map. (PS: Actually, sometimes you can type in numbers; but not always, even when it does know them.)

The "points of interest" database is fairly useless; one would want to be able to ask to be taken to the nearest food, say, or food near the planned route. Unfortunately, it's arranged like a phone book: after optionally entering the town name, one is taken to an alphabetical listing... Correction (27.4.): Actually, it is possible to ask for the nearest food, but not through the Destination/PoI menu. One must instead tap-tap on the map to get the context menu and select "Nearest PoI".

It has three map views (north-up, head-up and next turn) and three arrow settings (none, small and large), but it doesn't allow you to set them separately - there are three fixed combinations (north-up with no arrow, head-up with small arrow and next turn with large arrow).

Occasionally it assumes that you will follow a road even though it takes quite a turn through an intersection. This was particularly noticeable in Albury-Wodonga - the highway takes several 90° turns, only about two of which are announced as "turn right/left onto Hume Hwy". The head-up map solves this, as you simply follow the red line regardless of what the arrow is saying.

When re-planning, it doesn't take into account the re-planning and driver reaction times, so it'll sometimes end up with "turn left in 20m" as the first instruction (which leads to another round of re-planning).

Occasionally the head-up display gets confused and indicates that you're reversing...

No real way to use the unit on a table, whether the antenna is open or folded back.

Added (20.10.): No real way to mount the unit in the car except with the suction cap. There are no attachment points on the unit or even on the bracket.

It's closed source, so no-one can fix any of the above (even the most trivial), and it requires the occasional re-boot. It also doesn't appear to have any way of communicating with Linux. It identifies itself on the USB as some sort of PocketPC. (The memory card can be used from Linux normally, however; presumably one could load maps into the unit that way, but we haven't really tried yet.)

Added (4.6.): Once you drive past the destination, it cancels navigation. Often, it would be handy if it kept navigating until you find a park or until you manage to find the entrance.

Added (27.11): It very occasionally forgets where it was going (I think if some particular operation is done while it's replanning, but I'm not sure how exactly). Workaround: Always save the destination in the Favourites, so it's easier to get to again.

Pros

If a turn is missed, the re-planning is reasonably fast and good. One can ignore it while one knows the area and still expect it to be ready to help when needed.

It avoids u-turns when possible. Both the initial planning and any re-planning take into account the direction you're travelling, so it will almost always tell you to take the next road, or go around the block, rather than asking for a U-turn. The exception is divided roads, which it takes as two one-way streets; and of course if there is no other way through.

Added (14.5.): It shows house numbers on the screen as you drive past; this is very handy when looking for a particular address at night...

Safety

It's another source of information, and therefore another source of distraction. However, it's probably comparable to a human giving navigational directions.

The re-planning feature makes one less concerned about being forced to take a wrong turn or exit; thus, it may reduce dubious last-moment lane changes and the like.

Misc