I have used a couple of the standard version orchestra stands and while they were perfect for general use, I found that they struggled a bit with heavy loads and the plastic coupling between the upright and the flat music desk section tended of wear out (break) over time if you were trying to keep heavier loads in the correct angle to view comfortably. In fairness this was probably the result of me putting loads on the stand (big, heavy folders; heavy lamp assembly) that were beyond what was really intended.
However, the de-luxe stand has a metal clamp assembly between the tripod and the music desk part. This improves the ruggedness of the stand and I suspect it will increase the life of the stand even with non-abusive use. There is a slight drawback that the music desk part is slightly more bulky because the clamp is welded to the back and can't be folded down as much as the bog standard version, but as that folding down was part of what was causing the plastic clamps to wear out over time, I am prepared to live with the minor inconvenience. The price premium is only about ?5 for the deluxe version and I would recommend paying for the de-luxe.
If you're not going to adjust the stand much and only use lightweight music - the basic stand will suffice. If you're going to put heavier loads on the stand and adjust it / move it from place to place a lot - I'd recommend paying the premium for this stand.