On my last PC I found the firefly renderer almost unusable. The PC was good spec but cheap components and couldn't live up to its promises. Not a fault of Poser5. Even so, I wouldn't go back to P4. I had to use to P4 renderer in poser 5 for most things, but the other features, esp linked runtimes and nested folders made it worth the troubles. Having recently replaced my PC with something a bit higher spec (it's a 1.2G processor, 512k ram) I find P5 runs like a dream and I'm loving what firefly can do. Got to re-learn dynamics next. I agree with the above re. screen resolution, but I work at 1280x1024 anyway.