Is the Zu Audio Omen Mk1b upgrade worth it?

Hello,

I am looking for some guidance regarding the Mk1b upgrade for the Zu Audio Omen speakers. I have had mine for a few years and are quite happy with them. They are driven by 2 8 W tube amps and I mostly listen to older Jazz (Oscar Peterson for example) and Folk. 
Any thoughts are appreciated. 

Many thanks.