You should be able to pull a good key with either of those, IMO. In general having dedicated illumination for the green wall/fabric helps, as long as you're not overexposing. Higher-end keying facilities will use green lights on the wall (using gel might create a similar effect) which send some additional green light bouncing off the green surface.
Have you tried this with a person or object in front of it? That's really where the rubber meets the road, especially when you consider that you need to add lights for the subject, etc....
I do about 10 chromakey videos a month using this setup. It works good...but as I said I want to be better!
I had a spare gel lying around and saw the [G] (green) shoot way up on the scope....so I'm purchasing gels now. I just want to be able to have a better key.