Harbeth 30.1 or legacy calibre

I’ve heard both, own one. Audiotroy gives a very good answer, you will be delighted with either it’s matter of you deciding which one. Remember to factor in your decision that you’ll need a stand, fortunately there are available  stands for both.

This is an old post...i owned the Harbeth 30.1 for about 1 year and they were very nice. They were lacking sparkle and efficiency. 10 sets of speakers later i now have Audiovector SR3 Avantgarde Arrete. Highly recommended if you can find them on the used market. 
I heard the Legacy at a few audio festivals and they always sound very thin...not my cup of tea

I am shocked that you would call them thin. Big, rich and full bodied but still detailed in my experience.

while i prefer the sound of the harbeths, more natural and much more forgiving yet plenty detailed, the legacy calibres are different but quite excellent.  
the biggest difference is that you can put some serious wattage into them with biamping.  it isnt like trying to biamp a two way with an amp for just the tweeter.  one amp would drive the large midrange and tweeter, the other amp the woofer and passives.  crazy excellent bass is possible.  
they also come in active amplification mode as well, although i did not care for the occasional unforgiving sound of the class D active amp driving the ribbon tweeter.  

Planning on bi-amping my Calibres soon. Have a feeling that will be a big boost to an already amazing sound.