don't get the v6... that's about all you need to know
but seriously, the 22re gets better gas milage, has more aftermarket support, easier to find parts for, etc, etc, The weakness is the timing chain, if it's never been replaced you will probably need to.
the 3.0 has head gasket issues, tend to be a bit more unreliable and gets worse gas milage.
I am running a 22re that has 230,000 on it and it purrs like a kitten, never had an issue except the alternator.
that's my 2 cents for what it is worth, I'm sure someone with a bit more knowledge on the subject will chime in as well.