I generally prefer radials, but the rfc has its uses. For example, i am currently wiring a small work area for a company. The heavy duty kit has its own 3ph supply or runs on air. But they need sockets to plug in some lights and over a small bench area. I would normally have put the sockets on a radial, especially as the area is only the size of a single garage, however I cannot avoid running some cable in insulation, method 103. This reduces 2.5 to 17A. So I cannot put in a 20A radial, so instead I'm putting in a 20A rfc (I would have made it 25A but couldn't get a 25A RCBO without special ordering it).
In domestic and commercial the rfc also has the advantage of "reach". With it's substantially reduced volt drop compared to a radial and it's ability to share the load over two legs, an rfc can be installed in a largish area that might require several radials (IT considerations aside). Or it can be used to reach third floor bedrooms involving long initial runs.
Rfcs are also useful for high integrity earthing, as you don't need to install an extra g/y return cpc as you do with radials.
Don't forget that an rfc does not have to be 32A/2.5mm. Other ocpd/cable combinations are available!
Viva la rfc! (even though I prefer radials)