True , many people make the mistake to consider the bino itself.
That's the main reason I sold my Fuji 25x150 + UA P-gram mount.....150 pounds with counterweights and a real pain to set up.
The 120 90 seems to me to be the best all around choice for light gathering/ease of temporary setup/takedown and a lot easier on the back which is increasingly an issue as I age.
As C Eastwood famously said "A man has to know his limitations."
As far as i understood in this month the bino is nothing compared with the case . I belong the 120 and the bino is quite easy to handle... the case instead is not so easy as far as volume and weight concern . I cannot immagine the 150 case plus the bino plus oculars and accessories....