I would definitely go with the OHxF97.  I have read a lot about using callery seedlings for rootstock and have decided to abandon the idea.  I'll still topwork the existing callery trees, but i won't plant any seeds to use as rootstock.  People have reported a lot of problems with callery rootstock because of the genetic diversity.  If they're open polinated, they could be crossed with something else.  Comaptibility and vigor have been problems for a lot of people.  With OHxF97, you know what you are getting, and it is likely superior to any callery rootstock.