I know most of Ribbon risers are not shielded and the fact that cable's length plays a (significant) role in this too.
Also I saw USB risers rev 1, 2, 3, 4, 5 and 6, but I'm not sure what's the difference, they all look the same.
The one's I have had since LTC day's I have. Amazing how long some of them have lasted on part's. But I personally love USB riser's if I build a rig anymore. You get extra space to spread out card's. It looks much cleaner.
Either will work but once you try USB risers I think most will like them better. Just so many advantages at least for me.