People That Have Upgraded From Harbeth 30.1s....

.... what speaker did you buy? 
I upgraded  from a Harbeth c7es3 to a Klipsch Kg 5.2 .After listening  to the Harbeth for 6 months , I dragged  my Klipsch out and compared them side by side , the Klipsch  by far sounded better

Now I need to sell my Harbeth
I think the Coherent Audio line is speakers is a distinct upgrade in sonics from Harbeth.

They offer a Tannoy-esque coaxial driver arrangement, with a horn loaded tweeter inside the woofer that offers up a sensitivity of 96db.

Tube amplification will mate better with this speaker than anything Harbeth makes. So if that’s  important to you, I think taking a closer look at the Coherent GR10 or GR12 is very important.

Oh, and they’re literally half the price of Harbeths!