Zu Speakers upgrade


I recently purchased a set Zu Omen Mk1 for $300.00. They are in excellent condition. Zu allows for upgrading to the new drivers. Does anyone have familiarity with this? Is it worth the $500.00 net charge. I am presently using a NAD C326 BEE to drive the Zu's. What is a good amplifier to drive these efficient speakers?
coachpoconnor
I just took delivery of the Zu Omen Dirty Weekend floor standers.  Using them with a Prima Luna Prologue 5 tube power amp & Musical Fidelity CD PRE24 preamp/ cd player.

Very pleased so far.  

Would go for the upgraded drivers.  No brainer if you like the Zu sound.

Rich 
Rich, thank you for your response. I am picking up a Music Hall a70.2 ($750.00) from a local audio shop tomorrow to demo for 48 hrs. Will see how it goes. If it doesn’t work I’ll order the MF.
Just make sure that the Zu Omen floor standers are placed about a 1/2 inch or so off the floor.  The speakers have bottom ports.  The sound is not right if you place them directly on the floor.  

Rich 
Just make sure that the Zu Omen floor standers are placed about a 1/2 inch or so off the floor.  The speakers have bottom ports.  The sound is not right if you place them directly on the floor.  

Rich