We have not yet tested doing standard INSERTS into InfiniDB and benchmarking it against InnoDB...our current engine of choice. The presumption is InfiniDB will be much slower for obvious reasons.
From what I have read you have an excellent batch loader utility for populating the DB. Have you considered exposing this through an API for use? Most true applications cannot just do a batch load of data from a file. There is auditing that needs done, loads may come from 100's of client machines connecting to the DB through a middle tier server, there is rollback support needed in the case of something bombing out, etc. So being able to do these loads fast yet supporting a true production environment would be useful.
FYI...i am aware that your standard batch loader does not provide rollback support, but if a variant existed that does support this, yet is faster than a standard SQL insert, would be useful.