Firefly is still used by some and it may be more suited to the type of art they produce but I don't think I could return to Firefly after using Superfly so long.  Many of the vendors creating content for Poser include Superfly materials.  In such cases there is no conversion to be done as it only requires the application of the Superfly materials using a few mouse clicks.  There are also a number of Superfly materials that come with Poser 13 and other collections can be purchased such as Ghostship  Poser 12  materials from RPublishing - Ghostship2, that work fine in Poser 13, and Super Shaders for Poser 11 by VinceBagna that also works well in Poser 13.  I have not found the conversion of old materials to be difficult and I have converted materials from content I purchased way back in 2000. 

If you try Superbly and do not find it a step up from Firefly there is nothing wrong with continuing to use Firefly, it would however be a shame to stick with Firefly just because it is difficult to use, mainly because it does not have to be difficult.

Having said that I would add that lighting can be very different using Superfly but again, it is not difficult to adapt, I have managed just using trial and error.

Coflek-gnorg is one vendor who includes Superfly materials 

This is a scene using Blender and Firefly materials converted to Superfly

I am not saying for minute that these are fantastic examples of Superfly but examples showing the use of Superfly is possible with minimal effort.

 

 

I use Poser 13 on Windows 11 - For Scene set up I use a Geekcom A5 -  Ryzen 9 5900HX, with 64 gig ram and 3 TB  storage, mini PC with final rendering done on normal sized desktop using an AMD Ryzen Threadipper 1950X CPU, Corsair Hydro H100i CPU cooler, 3XS EVGA GTX 1080i SC with 11g Ram, 4 X 16gig Corsair DDR4 Ram and a Corsair RM 100 PSU .   The desktop is in a remote location with rendering done via Queue Manager which gives me a clearer desktop and quieter computer room.