It's always nice being handed absolutes, but there really aren't any when it comes to plants (or much of anything else).
Unless you're dealing with actual PAR measurements--or at least a defined tank dimension/light source combo--everyone's opinion on what constitutes a particular light level is going to be highly subjective. I've had high-tech folk refer to my shrimp tank as a "bloody cave" while low-tech folks wonder why I'm flooding it with so much light. Any supplemental sunlight the tank gets can be a total game changer as well.
Ditto on whether a plant is growing "successfully". Traditionally high-light plants that are brightly colored, large leaved and dense under ideal conditions can be healthy attractive specimens under very different conditions IF handled correctly.
Fertilization also makes a difference. In a heavily fertilized low light tank, my hyro sunset grows fast--but small leaved and lanky. Not real attractive. Same light level, minimal fertilization produces the same small leaves, but with such slow growth that the nodes between leaves are tight and it becomes a reasonably bushy plant again, just very very small.
One of the best tools I've found for learning what plants do under less common light conditions--other than direct experimentation--is browsing the tank here. There's also a thread in the low-tech forum that shows off how lush low-tech tanks can be--great to see how people have handled different plants and what results they've gotten.