I also think it has a lot to do with the situation. If I was in a Classic Rock band, Omnisphere 2 may not be as popular. Guido’s VB3 and Classic Keys from NI may take the cake. If I am playing a house of worship (contemporary) O2 may be more relevant. DJ/EDM - Serum or Sylenth is hard to beat (I would choose Serum). Piano I can’t comment on, as I am not really a pianist. I thought LL sounded good, but next to classic keys by NI, LL is parked more often than not. My home studio, I still use Steinberg products and switch between ProTools (which has a great audio capture ability), and Cubase which has great workflow and automation capabilities (I don’t like the audio recording in Cubase though). I own Ableton and Studio One, as well. Ableton I use session view live, mostly, but Ableton 10 is supposed to make their DAW more intuitive.
BTW, I own a UI24R and it works seamlessly with C3 to incorporate VST effects for vocals and instruments in a live show. I plan to heavily promote C3 on the UI24R Facebook page. C3 with UI24 is an amazing powerhouse for a great sounding show.