The advantages of Capillary film come from it's extremely low Rz. it's automatic OEM and it's extremely uniform thickness.
Rz. value is a little lost printing on T-shirts, but not completely. It still gives detail through the OEM (ie:edge detail) beyond what most meticulously scoop coated emulsion will.
The shops I've been a part of were fairly aggressive with the squeegee when applying it to the wet mesh, so it worked in there better than if it's just laid on top like some would tell you is enough.
If you want to have some fun, use some of the capillary release liner on a freshly scoop coated screen (shirt side) to dramatically lower the Rz. beyond what skin coats can. (some emulsions will work with this, some seem to adhere to the release liner too much) It wreaks havoc with EOM, but will give awesome Rz. for graphic applications.