Soundlabs are tough to beat. If you are going to replace them, my recommendation based on quite a bit of time listening to Soundlabs, is to get speakers with ribbon tweeters. Maybe Proac D 30r?
I have not heard the Jantzen speakers, but as someone else suggested, you might want to audition them as they are electrostatic hybrids.
I have not heard the Jantzen speakers, but as someone else suggested, you might want to audition them as they are electrostatic hybrids.