There is much to like in a speed graphic. It is a fairly rugged camera and thus if you purchase it at a low price, it is not a camera that you need to worry about damaging. The ability to use barrel lenses depends on the focal plane shutter. If that doesn't work right, then it is not such an attractive package.
They came with a rangefinder and if that works correctly with a lens that is on the camera, it is a plus. Some are for sale without a lens or without the original lens. This is less attractive. If you will put your own barrel lens on the camera, then you will need to verify that the groundglass is present and correctly installed (generally requires a test print of two to be sure that this works).
The drawback that you will note soon, if what you want is movements, is that they are very limited on a graflex.
Another point to note is whether it is a graphic or a graflex (entirely different type of back) and if it is a graphic whether it has spring back or a graphloc back (more versatile, especially if you will use a roll film back).