Ortho is the photo scenery that sits below your autogen. Tony's w2xp is designed to work with photo scenery. For example your photo scenery is a 2d surface. While in the air that looks okay, on the ground or VFR it would not look very realistic. Tony's w2xp adds a 3d surface layer over the photo scenery using open street map data. Using the sat photo and w2xp you will have an accurate real world representation in your simulator. This is very similar to what you saw in your 32bit sim, if you have any experience with for example an Orbx region. The difference is that orthos plus w2xp is a very accurate representation of the real world. It's so accurate that you would be able to fly over your own house in the simulator. If the open street map data is good in your country, there will actually be a 3d model of your house in the simulator generated by w2xp. At the moment OSM data is the best in Europe, second best in the US. So if you fly a lot in either of these locations, your simulator is going to really shine.
Do a google search for x-plane orthos for the various tools to create orthos for x-plane.
Check out this video as an example of what ortho plus w2xp look like. Clearly you can see in this video it blows away anything in the 32bit sims. At the moment the w2xp developer has released several regional, and highly detailed areas. Norway, Massachutes, Great Britain, and a few others. Every continent is available, but as I said before OSM data in the global files may not be as good as for example Europe. In those areas you will not have much 3D generated over your 2D photo scenery.