If those are the original low-Z (battery powered) EMGs, they are great pickups. I played a no-name fretless J for years. I finally upgraded to original EMGs. They sounded great, but mostly I wanted to get rid of hum and at the time I played a lot outdoors so I didn't want the strings grounded to the amp. The big fretless upgrade is to learn to play forte with the left hand and mezzoforte with the right, so to speak. You have to bury that string in the fingerboard or your notes will all sound "foof, foof" instead of singing. If you don't nail that, equipment changes can't help you sound better. Once you nail that, then maybe equipment changes will pay off, if it turns out you really feel a need to fiddle with the hardware after you get that gonzo sound.
"I ask Leo 'Why does one sound different than the other?' And he goes, 'It's mostly the resonance of the wood....I can't tell God how to grow a tree.'" --John K