Pianoteq Pro - Supports up to 192 kHz

What I think could be improved is that maybe after the upgrade I'll say "Wow, I wouldn't think it could sound so good", like it some surprising improvement I can't think of right now, having Pianoteq Standard.

I have more experience with Pianoteq in live playing but I compose music, and hopefully Pianoteq can sit well in the mix if I'll use piano in some piece.
If I remember correctly I used Pianoteq at least once or twice in a DAW production.
Also used Pianoteq a lot to record myself playing live.

My opinion is that you will not have that impression with the increase in frequency, unless you are very young and very sensitive to high frequency (which most male people are not, especially past their 20s or 30s), not to mention the response of your speakers or headphones. You can do the reverse and reduce the frequency in the options and see if it makes any difference to you. It almost doesn't for me. Where the increase in frequency may matter is if you are doing lots of edits in which higher frequency means "pushing" the digital noise to inaudible frequencies. For minimal editing and live playing it should not matter at all.

In my opinion the most important (and least used) setting for PTQ is available even in the Stage version and it is the velocity curve. I've just learned that minimal tweaking there cause massive difference in both touch and sound.

Back to to Pro version, I think it can be useful if you think you can improve one section of the compass (e.g. would like a brighter bass) without affecting a different section (e.g. you do not want a brighter high register). The note-by-note editing allows that and it's very nice to have, however it's very tedious and time consuming to do -- you can try that with a few parameters in the standard version. I wish there was an option to select only a handful of notes and have PTQ interpolate in between. Perhaps you could do that in Standard with layering? I have not tried.

I used the standard Pianoteq version for a while before using Pianoteq pro. Pianoteq pro expanded frequencies does not make a noticeable difference in the quality of the sound. (96K versus 48K), on the other hand the CPU consumption is very notably increased with 96K and beyond.
For a professional project with a daw, expanded frequencies is undoubtedly justified by the standardization of the formats used throughout the effects chain. Although I personally use the 96K format, in standalone mode I very rarely got an improvement in sound compared to the 48K 32-bit format available in the standard version.
Pianoteq pro is in fact interesting especially for adjusting the settings of a piano note by note. (adjust, to be closer on a given key to the sound of the acoustic instrument than the instrument model proposed by Pianoteq, or on the contrary to deliberately move away from it)

Bruno

Real pianos that are not new often have slight but noticeable changes from note to note, perhaps because some notes have been played much more often than others, and because of simple aging. These changes are not desirable, exactly, but they may give a sense of reality to the player, and may give the piano a unique character. They may affect composition and improvisation, as well--if one note has an upper partial that rings out a bit, it might combine with other notes in interesting ways, or produce a singing tone that fits well in some chords or melodies. Often, slightly different tunings of the unisons create this sense of realism and character--the strings go out of tune at different rates, so if we sit down at a piano with all of the unisons tuned exactly the same way, the sound may seem artificial, even if correct. A matter of the "uncanny valley" perhaps? Imperfections more closely resemble reality?

I agree the note editing and tweaking features are what really makes Pro worth it at least for me anyway.

As Jake Johnson noted, real pianos are not perfect, and this is where we can make up for the perfect digital models we have. This is the nature of the beast with their wood, felt, and other materials all assembled more or less by hand even in the factories where there are CNC and robotics.

As pianos age, the parts wear in various ways. Bushings loosen up, making some hammers move quicker than others, hammer heads become firmer on some notes, little buzzes occur that add to the sound as part of the natural aging of the piano, and even a recently tuned older instrument can sound sweet and even warm compared to a brand new one.

A recently tuned instrument reminds me of a vase of cut flowers. The first day its fresh, but as time goes on there's a bit of fading and smoothing out of the colors and even that warmth about it that comes on as everything smooths out. It's this what we want to achieve and get away from the perfect digital world. Achieving what we want takes patience. I have spent many hours tweaking and poking with varied results. In most instances, I ended up deleting the files anyway after listening to them later.

Hint: If you make any changes, check them later. At first blush, we think they're superb because this is what our ears want to hear. Letting them sit there and going back later gives our ears and brain a break and allows us to hear them fresh and from an outside perspective. I also do the same thing with my recordings. I wait a day before I edit in order to let my ears hear the music rather than my brain replaying it as I thought it should sound. It's usually then that I decide whether to keep it or not, and usually end up deleting them.

I didn't know that.If that's the case, that may explain my poor ability to come up with something decent.