PGGB is great.
PGGB (the full version, the RT version is a bit slimmed down) is from a technical standpoint the most accurate Nyquist reconstruction tool available.
The Nyquist reconstruction filter itself uses the maximum number of pure sinc coefficients possible given the number of samples in the file, ie: it’s taking Nyquist theorem to the maximum possible extreme within the constraints of the fact that we don’t have infinitely long audio streams.
And then the noise shaper it has allows you to get higher dynamic range in a 24 bit file than would be possible even in a 64 bit file with standard dithering or without any noise shaping.
Basically, PGGB is as accurate as it gets. It gives you the most accurate possible reconstruction of the audio contained within the file you feed it.
BUT the main argument as to why PGGB wouldn’t just plain and simple be ‘the best’ is that recordings/production aren’t done perfectly and some of the stuff close to the Nyquist frequency you may not actually want to reconstruct. ADCs and digital resampling tools in DAWs don’t have perfect filters and so by perfectly reconstructing the audio in the file right up to the nyquist frequency, you also are now inadvertently reconstructing some of the aliased/incorrect content that was “baked in” to the file due to the imperfect recording/production methods.
For this reason sometimes an apodizing filter like HQPlayer’s Sinc-M or some of the gaussian filters can help by slightly limiting the bandwidth and filtering out some of the ringing/aliased content that you don’t really want to reconstruct.
But it’s just a question of ‘accuracy’ vs a potentially more practically ideal result.
Personally, given as nowadays DAWs even just by default usually have very high performance resampling/filters, and ADCs are getting better, I prefer to go for the most accurate possible option. I find that PGGB sounds better than HQPlayer most of the time to me, and I don’t really want to limit the accuracy of the reconstruction to potentially avoid including minor issues in some tracks. Frankly if they’re there that’s a mastering/production issue anyway.