Considering Harbeth C 7ES-3

The C7ES3 treble is incredible and best in the Harbeth line IMHO.  
Possibly the nicest sounding application of an aluminum dome that I have ever heard- natural but with a shimmering amount of air that adds trailing edge detail without going too far.  
The P3ESR and 30.1 / .2 use the soft domes and they are too rounded off for me.  
The SHL5+ have a super tweeter that while impressive does have some cancellations with the main tweeter that give the C7ES3 the edge.  
The 40.1 /2 sound overly natural with a rounded off top end and dominating bottom end. 
Again with the right system synergy and room setup the C7ES3 are spooky good speakers. 

thanks for the helpful overview. 

The Super HL5plus is DEFINITELY not lacking in treble, either measurably or sonically.  It sounds open and airy.   The C7 didn't sound lacking to me either.
The 30.1 was a tad darker sounding than the two above, but still very nice.

Agreed, no lack of treble with the 7’s or SHL 5’s.

@avanti1960
FYI, the P3ESR and the C7 does not use a soft dome tweeter. It’s aluminum!

Harbeth P3ESR loudspeaker. The fundamental design of the P3ESR remains unchanged from its predecessor: a 0.75" (19mm) ferrofluid-cooled aluminum-dome tweeter, protected by a mesh screen (in this version, black instead of gold), is coupled to a 5" plastic-cone woofer, mounted on the front baffle from behind.