I am making a series of test and experiments with LuxRender.
I have other approach and work in an independent way, I don't use PoseLux  and rely on Poser or Blender for export to Lux. I made a stand alone converter that converts any Poser, obj or 3ds files to LuxRender material and geometry files and it was finished and working.
My goal was not to make or take a scene in Poser and render it on Lux instead of firefly, I almost do not use firefly for my images!  My goal was to test and use LuxRender for creating images.

Some comments:

• LuxRender is different from Poser, lights and materials are different. To render a scene in Lux you must create a scene for Lux, if not you are losing all the features and potential of Lux.
• Some things can only be done in Lux, other can only be done in Poser and other in both.
• LuxRender is only a renderer, you must model, pose  and mount the scene somewhere.
• The materials once exported from somewhere else must be reworked to use Lux materials and use their features and potential in the scene.
• It would be very useful an application for mounting the scene, lights and materials in Lux, the only thing that I have is a text editor.
• The materials once exported from somewhere and edited can be very powerful.
• You can create a model and material library for Lux.
• You can pose an object from the library.

Positive things about Lux.

• The material structure of Lux is very powerful. You can change the skin color of whole Vicky4 changing a RGB value in only one text line.
• Once you have an edited material, for example Vicky4, you can use this material for any other
   scene where you use Vicky4 with the same textures. Is the same as MAT poses.
• The same material can be used by other repeated figures/props in the scene.
• I suppose that the same must be done with geometries using the Transform command (not tested yet).
• You can have stand alone shadows.
• The renders can be fast if you had luck setting all in the proper way.

Negative things.

• The lack of ambient color.
• Area lights cannot have a transparency mask.
• Is very hard to work with lights. LuxRender self adjust with illumination and many times get lost. A little change on a light and a good scene turned into a crap.
• Lux render is not physically correct as their propaganda says.
• Shadows appear from who knows where.

About speed.
Rendering speed can be very fast or very slow depending on your luck.
You can know this in advance with this:
Once LuxRender has completed the loading of the scene and begins to render after some seconds you have two possible scenarios:

A- The image is very noisy, crappy and continue to be after some minutes.
You can be sure, it will take a very long time until you get something that is acceptable, if it is .

B- After few seconds appears an image and is good.
 You have a fast rendering and the image will improve with time, but with insignifficant changes with more time.

When is A and when is B, you don't know. You can turn from A to B or from B to A changing a bit the illumination.
There also exist a third alternative.

C-  You start with B, but after some minutes it turned dark and into A. This means that LuxRender got lost with its self adjustment, threw into the trash all good that was done and started again in a crappy way. The final result is unknown.
  

Stupidity also evolves!