Yes, but not all business classes are the same. The UC product, especially on a/c equipped with the suites, has many features that you would associate with first class: privacy (individual seat separated from other pax), duvet, PJs, limousine service, on-board massages, superb lounges, including very nice arrival facilities at LHR. They also have an excellent IFE and, of course, a very comfy genuinely fully-flat bed. Compared to AF C class, it would be a no-brainer, imo. VS would win hands down. Compared with F, it is more of a challenge. One thing that lets VS down is the inconsistency of onboard service. You can have a wonderful team but also a rather indifferent one. Food-wise, I would expect AF to be more reliable as well.
For my money, if there is a big price differential (and there usually is), VS UC would offer, imo, much better value than AF F. But to each their own.