Biggles, I'm glad for you that you enjoy the PA5x so much, but it's far from as black and white as you make it seem.
PA5x: Excellent build quality, nice chassis, tiltable screen, the Fatar semiweighted keys on the 61 and 76 versions are even nicer than the Tyros/Genos keys, yes. Not a fan of the much slower 88 key version though.
Additionally, the bass compression really makes the drums and bass punchy, and Korg has always been a world leader in synths (especially pad synths). The pianos blow the G1 pianos out of the water; only the U3, Felt piano, and Character Grand on the G2 are comparable.
Now for the not so good (depending on your needs); no registration sequencing. So all of my youtube videos would not be possible.
So S.Art2 phrasing on the PA5x doesn't automatically shift mono/poly; so when you do a sax gliss, for example, the fall off sample will still sound on top of your original note, unless your timing is inhuman (Yamaha's had auto switch from poly to mono for phrased articulations since the Tyros 3).
Korg's synth strings and pads are superior,
but even the strings (and brass, and woodwind) on the G1 are better than the PA5x's; the new improved brass on the G2 even more so.
G1,G2 and PA5x all feature round robin drum cycling, and all sound fantastic, but the Revelation reverb on the G2 isn't just marketing buzzspeak; long story short, when I play the same style/ midis on the PA5x, Genos1, Genos 2 (I have them all hooked up to the same speakers), the G1 and the PA5x sound "canned", but the G2 sounds more "real"
Here's my midi recording of "Fever", optimized for G2. What you hear is the same as the quality of the styles on board.
drive.google.com
Here's my midi recording of the same file, optimized for PA5x.
drive.google.com
Plus being able to search for voices, styles, registrations, and songs, is a godsend on the G1/G2.
Having said all that, *not* having SSS on the G1 or G2 (well, technically you can if you jump through hoops, but it *should* just work out of the box), the much more toylike build quality of the G1/G2, the much punchier bass compression on the Korg; if you don't need a lot of sample library (it's been over 2 years, no old packs have been made compatible, nor any released for the PA5x yet), and you just want to play it 'out of the box', it *is* still an incredible instrument.
PLUS it has a separate guitar input jack with full amp modelling... your guitarist literally can just bring his guitar, no amp, and run it through your PA5x in to the same PA speakers. Yes, technically G1/G2 can do this too, but at the expense of the vocal mic; PA5x you can have both the guitarist and singer running through the same board, with independent DSP's for both.
It's far from a simple "This is so much better than that".
Mark