I really enjoy using my digicam to preview composition. However it is not a flawless system. The screens tend to be high-contrast and the chips are not very sensitive in low light. Size does make a difference. One of my shots with 35mm went unnoticed for a year because I was only loooking at the negative and contact proof. Turned out to be one I received an award of merrit for in the state fair.
One time I brought a little 3mp digicam with a small screen with me.. I was in the mopnterey area and took some photos of the 'lone pine'. The digicam pic turned out better than the LF ones.
So... my advice is if you use any type of small format for research, make sure you have the options to see it full size and reshoot before you leave the area.