I can hardly call myself a pianist. Started playing with retirement and still get the grasp of it after 3 years practicing. But pianoteq helped a lot along the way. Not for the sound alone but the pianos respond so subtle to my playing - I can feel a connection with the Instrument I never had with sample libraries (And I have played with a lot of high quality ones). You have to try to understand. And trial is for free.
Two of the biggest advantages of a modeled piano/keyboard virtual instrument like Pianoteq are the small load size and RAM requirements, and the number of velocity layers. Using current MIDI 1.x, you have OFF (0) plus 127 velocity levels. With sampled libraries, I'm going to guess that 8 layers plus 3-4 round robins would be a LOT, resulting in a huge library.
I spent a lot of money to get a 2 TB Thunderbolt 3 SSD for my sample libraries, and have two 2 TB USB3.2 SSDs for other things. Pianoteq is small enough to just reside in my VST folder on my internal 1 TB SSD.
There have been major improvements in sound quality as Pianoteq has advanced through major versions. It just keeps getting better. Even the entry level Pianoteq Stage version is super usable and plays ALL of the available instruments. If you have no need or desire to tweak things, that's all you'll ever need. Except for buying additional instruments.
Pianoteq Stage by ModarttI "only" have 8 instrument packs plus the freebies, but I'm certain that number will grow.
C. Bechstein DG, Steinway Model D, U4 upright piano, YC5 rock piano, Petrof AP275 + P284, Blüthner Model 1, Grotrian Concert Royal, Electric pianos
Pianoteq Free InstrumentsEDIT: OK, make that 9 instrument packs. I just bought the new Classical Guitar pack. That's what I get for clicking around on Modartt's website.