To Harbeth or not to Harbeth, That is the question...

I have the SHL5+ 40s in a 13' x 16' room.  No experience with the 30s.
For low to mid volume listening, they clearly are better than my LS50s, LRSs and B&W Matrix 801S2s.

My 1970s Rogers LS3/5As however, are right up there with the SHL5+ 40s for low volume listening.

Agree 100% with @chayro 
 '' I've owned the SHL5, Monitor 30 and P3s. IMO, the SHL5s had a bigger, smoother sound and are more tolerant to equipment and cables than the others. ''

Very tolerant with the numerous amps, cables and stands that I have used.

@voodoochillin - I rotate between a Hegel H190, Forte 1A and a pair of Ampzilla 2000 2nd Edition monoblocks (Bryston BP26 preamp).

My SHL5+40s sounded great with the above SS amps. Best with the Ampzillas at higher volumes and with complex music (concertos, symphonies, big band jazz).

A few months ago my uncle gave me a Jolida SJ502 tube integrated. This is my first tube amp and I have only used it at my new place.

They really shine with the Jolida. Different in many good ways. Perhaps lacking a little bass compared with my SS gear. Can only imagine how they would sound with a higher end tube amp.

But this is where the subwoofers do their thing. And very nicely.

I also have used them in 4 different rooms. A 10’ x 12’ office and then an open space 14’ x 16’ living room at my old place.

My home office at the new place is 13’ x 16’.
There is also a 15’ x 19’ living room.

I have run them full range with and without subwoofers (4) in all mentioned rooms at both places.

I can definitely vouch for the high quality low level listening.

Hope this is helpful.