From my understanding, the differences between the 220s and the 330s are Bass.
(I did not learn all this myself, so I am paraphrasing what was tought to me when I was researching).
With the 330s, they come with two Bass Drivers and two smaller midrange drivers.
You are taking a bit of compromise with the midrange for the sake of base as the midrange drivers are smaller. However for you, that may be a good thing as you will get some decent bass without a sub with the 330s.
If you already have a sub, why not get two larger mid-drivers and let your sub handle all the base.
I have personally listened to both the 220s and 330s and could not hear any difference between the two, but when it comes to speakers, yuo should really hear them for yourself, don't trust anyone's ears but your own (and your wife's
If you think 220 v 330 is tough, wait until you get to the ADP debate, lol
did that help?