Not beneficial for the HOME user (although I have my place cabled with "Level 7" (pre- standard Cat6). Why? it was new construction and I could get it. Panels, plugs, cable & outlets are all Cat6 or better.
For a company that's going into new construction or rennovation (or just deciding they have the budget to upgrade their infrastructure), going with anything less than Cat 6 (IMHO) would be a stupid thing.
There is just no telling what may be coming down the road, having the best possible infrastructure in-place is a good thing.
For an installed cabling system, the difference in component price is nothing compared to the labor costs.
FWIW
Scott