There doesn't seem to be much information about this subject. Intel support staffer Colleen Culbertson - a RealSense expert - said in a blog post about scanning a couple of years ago though that the F200 was better for scanning small objects than the R200.
Colleen said: "While the Intel® RealSense™ F200 and R200 cameras each have 3D scanning capability, they should be used differently and have different "scopes". The user facing F200 camera is best used for face and small object scanning while the R200 world facing camera should be used for full head, body, and any larger object scans."
"Objects smaller than a few centimeters, or larger than half a meter, may not work as the target."
Here's the full article.
As the SR300 is the next-generation successor of the F200, that makes it likely that the SR300 is the appropriate choice for your needs. The SR300 also has an official minimum depth capture distance of 20 cm, whilst the R200's official minimum is 30 cm.
I guess the most important factor is whether you want to make a 3D scan of an object or track its movement (e.g hand tracking). The camera can follow the tip of a finger, which is about 1 cm in width,