I’m looking to improve my sound with my next upgrade.
That’s too vague to make any meaningful recommendations. What specific areas would you like to improve? If that’s at all hard to answer then the best thing to do is go listen to other speakers to see what you might like better. If you don’t have some good dealers that are close enough then go to a major audio show or two so you can hear many other speakers and then go from there.
Another option if you like what you have but are just looking for “more” then adding a couple good subs can make a world of difference and be a huge upgrade. The X3 only goes down to 35Hz so there’s likely a lot more to be had by simply adding subs. Just another thought FWIW.