the superlumis picture is brighter and a bit sharper (at least the one I compared to my lumis).
I think the brightness of a superlumis with an old lamp, will still match the light output of a lumis with a new lamp ;-)
but again, when you get used to the higher light output, you wish to have even more ... ;-)
in my opinion, the lumis is still one of the best projectors out there. I recently added a lumagen to my video chain and it had a huge impact on picture quality! so if you like to get most out of your already near perfect lumis picture, that´s the way to go!