Yeah, I know how spamassassin works. A whole bunch of URLs
with an "organically" defined weight to them. Then as
spam changes you need new rules and new weighings. It is
redundant to my hand tuned rules, and slower since mine
are headers and first five lines of the body only.

Since yesterday, ifile has operated on 322 messages of
mine and only gotten two wrongly sorted (both were classified
as nonspam, one had a base64 encoded body, which is ignored
by ifile).

I think this is a your-mileage-may-vary thing.