dav1111 said:
Displaying a feed from the GNC300XL on an MX-20 would give you a little more info but I don't believe they would give you the runway overlay nor would they give you the terrian feature. You really have to fly behind a GRT WASS moving map GPS to appriciate how great they are.
I haven't flown with a GRT moving map, but I've flown with the MX20. Here's what I really liked:
* Ability to have the map look just like a sectional.
* Ability to have the map look just like a IFR low level chart
* Ability to show VOR compass roses on the "chart", along with your current radial, if you're using a SL30 (these are both ex-UPSAT devices)
* Ability to show approach plates on the map.
As far as I understand, the GRT doesn't do these, particularly being able to set up the map like a IFR low-level chart or have the approach plate. The MX20 / GMX200 also has a higher screen resolution, and I think this is why the GRT just doesn't provide the information - it doesn't have the resolution.
The GRT is a really good system, but it doesn't have the flexibility of the MX20 / GMX200 in terms of mapping. What the GRT does do is provide an integrated system for a low cost, less than 1/2 of the GRT. However, I'm big on human interface issues, and having the map look like a chart is a good idea in my book.
However, as always, this is America (sorry international readers), and we have a choice.