I've found (with the Brightside) that you can apply a lot of pressure (like A LOT) to get the paint to come off the roller nicely.

I also found that you should work the paint out with like 10 passes over the same spot before you move on. I guess it's 'cos even the high density foam doesn't mean that the entire area will get paint on it.

Both of these methods seemed to work well after the first coat or two. Before that and it comes out like a load of dots.