> Based on experience, are they really equivelant? If not, which is the preferred software to use?
These two products are quite different, and serve different purposes. NG Topo! specializes in maps, while Garmin MapSource just does contours (but is required to load contour maps into a Garmin GPSr). I use both, for different purposes.
NG Topo! provides 7.5' (1:24,000) USGS topo quads for the entire state (plus 1:100,000 and 1:500,000 for continental US states; AK and HI are different). These are the graphic equivalent of paper maps I would recommend for cross-country travel, since they show surface features as well as contours. It's easy to trace out routes for a quick elevation review or to print on a map, it's easy to load routes and waypoints to and from my Garmin (serial) GPSr, and it's especially easy to print the maps I want, at the scale I want, without stitching together TIFF files or screen snapshots. It also allows me to easily save sketched trails, notes, and other stuff for reference on future trips. I've found that NG's topo maps are often more recent than the topo maps on the free sites (15 years newer in some cases). Whether it's worth $75/state depends on what your time and effort is worth, I guess. I use free USGS quads too, but mostly for states I don't have in NG Topo!. Here's a map I made with NG Topo! (the numbered patches are live links to my map annotations).
Here is the same area in Garmin MapSource. These are the highest resolution contours available in MapSource.
There are no UTM collars on MapSource's printed maps; it's just what you see on the screen. You can poke in waypoints and routes in MapSource, but I use NG Topo! for that. The sole advantage of MapSource is that you can load these contours (not just waypoints and routes) into a Garmin GPSr; the GPSr's built-in database only has roads and other objects. No other product can load contour data into a Garmin GPSr. These contours on a tiny GPSr screen aren't really useful for cross-country navigation, but they certainly help when you're trying to get a quick orientation or are sketching a route from a trail book. I hope this helps you in your decision.
>FYI, I had discussed learning good navigation with some well traveled hikers and they all suggested a simple GPS, map, compass, Vector combination.
I agree. I carry a paper map and compass even if I have the contours and routes in my GPSr; I don't like to rely on anything with a battery. However, when hiking through jungle with no reference points visible, a GPSr makes it much easier to track your position.
There's another product that looks good, but IMNSHO isn't: DeLorme Topo USA 5.0. It has maps for the entire US on one DVD. You can plot contours as tight as you like, but that doesn't avoid the fact that the underlying grid is spaced too far to be useful for cross-country travel. I compared the resolution on some features, and found that the actual resolution was no better than MapSource's contours. Cliffs look like smooth hills, that sort of problem.