...to my ears the ATCs noticeably compressed at high levels (this was most noticeable to me in big orchestral works, they never sounded quite right at proper orchestral volumes).
Anyway, yes, the ATCs are not as good as current designs. But they are still excellent monitors. There are just (even) better options out there today. I cannot comment on value for money. FYI when I bought my pair of SCM50ASLs their RRP was half their price today (and incidentally not far from what a pair of 8361s retails at today).
I did have an afternoon's listen to the 200A's as they then were (twin 12" bass drivers laterally disposed) with the m,arge amp/crossover box set between them and umbilicals with 'Burndy-type' plugs and sockets to connect them. They made 100A's such as I used sound small and more constricted, but you'd only know in a kind-of direct comparison. the 50ASL's sounded a bit 'smaller' again but even then were way above the kind of domestic boxes we had access to.
It does or did seem easy to make ATC actives sound constricted or compressed somehow and I suspect lack of power in the standard amp packs was a possible issue (their electronics designer/director Tim Isaac once commented how the 50 bass driver could POP with '
Pearls a Singer' but not sure if this was a live monitoring or the mix-down itself. I heard a set of their limited edition 70ASL's (fugly silvery boxes) with their own top preamp (itself suspect back then if mine was anything to go by) and a Linn CD12 - I couldn't believe how 'in the boxes' and 'bland' the sound was... The 100ASLs and 150ASLs I heard far more recently with their latest preamp driving them sounded delightful at lower volumes (I freely admit I have no experience or exposure to Genelecs nor Neumanns, let alone other new models, so it's a purely personal subjective view in comparison to the other passives I've heard more recently).