Indeed, OrbX FTX Global is well worth the money.
You have to keep in mind that these are JUST new ground textures.... but the whole world is covered. The amount of data is impressive.
Of course, you must also keep in mind that, since the package contains ONLY ground textures (and autogen), your terrain will look only a bit better than default.... Until you also install a landclass !! Then it will really blow your mind.
As we all know, in default FSX, most of the areas have a very bad default landclass. The coasts are imprecise, the rivers follow stupid paths (climbing on the mountains, not following the valleys etc...), towns and villages are often missing, deserts are all over the place, forests are either too small or too large, cultivated fields where there should be cities or forests, etc.... This WILL NOT CHANGE with FTX Global.
FTX Global brings new clothes for your terrain. But you'll need a good landclass to tell your terrain that the pants go on the legs, not on the head. See what I mean ?

FSX, even with default textures, already does quite a good job once you give it a good landclass for a given area. But this area will start looking terrific once you ALSO give FSX some good textures. That's what FTX Global was made for.