Fedora in test then RH AS in production gotchas?

[kaze]

For testing and training purposes how does Fedora Core compare to Red Hat
Advanced|Enterprise Server 1.2|2? What might I miss by running Fedora in the
test lab planning for an entitlement requiring distro in production?

For example I want to play with Oracle, practice installations and whatnot,
but without paying for entitlements I can't patch RH AS 1.2 enough to even
install Oracle App server 10g.