Should I upgrade my Advent 5002 speakers?

You might try rebuilding the crossovers first , if you look up images of the 5002 you'll see that they are a simple design so upgrading the resistor , replacing and upgrading the 2 old worn out electrolytic capacitors ( electrolytics degrade over time and those are very old ) should make the speakers sound better than ever !   So for under $30.00 per speaker you can love your speakers even more .

Should have mentioned that the crossovers have been rebuilt already, but always good advice for older speakers.

@jasonbourne52 I really do like the Advents, but guess I’m just wondering if they’re a weak link in my system.  My listening is mostly jazz and rock, with a little classical thrown in from time to time.  Bass is only important in so far as the can accurately reproduce it, but I don’t want it thumping when it shouldn’t be.  I’d like to keep the size pretty close to the Advents and the price under $4000.  I’m more concerned with accurate than loud.  The MoFi speakers seem to fill both of those desires, but they’re still pretty new so there’s not a ton of info on them yet but what there is is glowing.  

How about this: the speakers that impressed me the most over the past several years have been the Ohm Walsh Sound Cylinders! I bought a seond-hand pair quite cheaply. They may be the best sounding and better than any of the other speakers in my collection! And this includes my Quad 57's! Stunning 3 - D room-filling sound from any spot! The performers are right there in the room! I am impressed! Ohm Acoustics in Brooklyn, NY can probably build you a pair of Sound Cylinders in the finish of your choice. You can contact and speak to the owner John Strohbeen. Ohm has been established over 40 years!

Except for the size part, it sound like you might like Vandersteens.

Stand mounts...if it were me I'd go with MA Silver 100s. But that's just my personal taste.