It's not that the G string has a weaker output, it's the voicing of the string in relation to the rest of the strings, which can make it sound imbalanced. There's an inherent thinness to the tone, depending on your string gauge, type, and pre-amp. Not so noticeable when playing fingerstyle, but slapping, it's definitely there.
The '97 definitely was more noticeable, though adjusting the PUP's height and switching to a .50 string gauge helped (and practically disappeared when I switched to flats). But the general tone of that G string regardless can be considered a key element of the Stingray signature sound, IMO.
That's the very problem I'm having with my SR. the G just doesn't sound the same as the other 3, its not a volume issue just a diff tone, it really bugs me when I slap, as the sound is so different.
Tried upping my G to a .50 from .45 but no real difference from what i can hear, would you suggest flats then to help even the tone? i LOVE the sound from my bottom 3 strings, just the G that;s bothering me