The 50 bass unit will bottom out in high level monitoring (their electronics designer once referred to a song 'Pearl's a singer' of the time where the 'P' could cause issue played flat out into 50A's.
I don't believe it's possible to hear the Neumanns or larger Genelecs and so on in a dem situation and domestic visits to studios aren't really on the agenda! ATC's and PMC's are often available for domestic people to hear and if you're lucky, Kii's and D&D as well! trounble is, all these active models are a one-shot purchase and a dealer probably won't see the client again for a long time (forget passive ATC three ways, they don't measure right for genuine reasons concerning the mid dome and are probably only sold as a revenue stream to dealers who don't know or care, as the latter can sell ever more expensive amps to drive them - I have a lot to say about this but best not). What's the motivation to sell a superior seventeen grand (£) active speaker when you can sell a fifteen grand passive models and a twenty grand Naim amp system with further room for upgrades.
Believe me, before annihilating ATC as a brand, you want to look at the domestic market around them (I acknowledge the pro market has evolved and changed in the last twenty to thirty years). Speakers like the top high tech (but still passive) Dynaudio Confidence, PMC 'Fact' models and Kudos Titans are three options available locally to me and all of them are severely wanting in my opinion, no matter how they're driven (Titan 808's driven my a hundred hrand of active Naim is 'nice' but hardly earth shaking as I'd expect for that money).
I miss my 100A's so much. Having heard current 100ASL's sound so good at lower levels, I shed tears all over again when I heard them. I could happily live with another pair, even though 'better' may well be available, as I like the sound character in small to mid size UK rooms. The bass is dry with no boom and that suits fine and the larger models never shriek to my ears as many 'HiFi' high end speakers do.
P.S. The original 20ASL Pro's I had also had the upper mid lift I don't remember my passive pre 'SL' sdamples having. The pro's had a bass lift control but the bass wasn't as smooth and 'tuneful' as larger speakers generally give, being of a 'thumpy' nature (I unkindly called it 'stunt bass' at the time). I have to say I didn't find this mid-forward aspect in the passive cheaper SCM 11's which have a slightly more conventional bass driver I believe - floor stanbding 19A's are also low bass shy I remember. Active 40's are nice for smaller rooms and would be perfect for me if only herself could stand the looks.
P.P.S. This may have been discussed before so apologies, but if I could afford a larger Genelec or Neumann, I feel it would be difficult if not impossible to get a meaningful dem anywhere in the UK especially East Anglia, unless a pro dealer in Cambridge stocked and demonstrated them...