Personally I prefer a fresnel, the best combinations are the one piece fresn/screen (& cover glass0 sold with Wistas, or the Beattie screens in my experience. A Maxwell screen would be similar. I use a fresnel on the rear of my Crown Graphic and that's not too far behind in terms of brightness and usability.

As Steve says if the camera comes with a plain screen then a fresnel has to go behind not lens side of the screen. I've made screens for Shen Hoa's and they are brighter than the originals.

Ian