Superfly is great, you just need to learn to tweak the settings properly. The default lighting is absolute garbage. I'm not really a fan of IBL so I can't offer any advice there, but area lights work excellent in Superfly. You can follow just about any real-world photographic tutorial and replicate the lighting in Superfly and get similar results.

Softbox Lighting Tutorial

Delete all the lights in the scene. Start with one area light (which is basically a softbox), set the render to a small size (400x400), low samples, and disable advanced raytracing like caustics/volume/transmission and even transparency, and just move the light around (in the beginning you can use point at -> and point it at your figure's head) and do quick 1-minute test renders until you get the lighting the way you want it. Then you can add a fill light.

I'm not going to lie, a quality render takes hours, but it did so in Firefly as well except with (technically) inferior results, and it does so in Iray as well. Preview renders at low settings are the key: I'll spend time in a small preview mode rendering a dozen quick grainy renders until I get the lighting exactly the way I want it, then when I know what the results will be like I'll bump up the settings and let the render run for hours while I watch a movie or sleep. You should never be 'experimenting' with large renders at high settings: your preview renders should already give you a very good idea of exactly what they're going to come out like.

Progressive rendering is great because you can let it run and see the render taking shape, and stop it if you notice any problems.

Also you should be abusing the hell out of the Area Render tool. There's no need to render a 2000x2000 image with caustics and 16 transparency bounces. You can render a scene at relatively low settings and then go back and render complex parts like eyes with a higher setting. Same goes for if you screw up and have a foot off the ground, or a spot of pokethrough or other problem: just render that small area. In older versions of poser you could see a line around where the Area Render rendered something, but now it blends it seamlessly into whatever render you have selected when you use Area Render.

I've been rendering my images at very low settings, typically like this:

Preview:

Render:

Area Render (Eyes, troublesome hair spots, etc):

It may be slower running the render with your CPU instead of a GPU, but that can be tweaked as well and on modern processors shouldn't take too much longer. If you do have a sluggish computer or laptop then you can set things up via quick preview renders, then before you go to sleep hit the render button... and wake up to a finished render.