oujee,
I should probably stay out of this one, since I don't have frets...
But I used to play regular guitar (you know, the one with the funny tuning?), and just last week I looked at the neck under a large magnifier. I happen to have one of these cool things on a flexible arm, with a large lens and circular fluorescent light, which I was using to cut down the nut slots on my bass.
Anyway, I was astounded to see that most of the (original) frets on my '63 guitar were almost totally flat - really flat, like a 1/16 inch flat spot on the lower ones, and only the 24th still looked round. The funny thing is, it still plays like a dream, presumably because the wear is nice and even. I don't play it much anymore, but I have a friend who comes over and after the first few times he stopped bringing his own new Telecaster.
(Keep in mind that it's late, I'm feeling talkative, and just making this up as I go along. I'm sure others will chime in with more practical experience.)
In theory, I can imagine that the advantage to having nicely rounded frets is that if they do happen to come into contact with the strings, there will be a smaller surface to generate buzz. But it seems to me if they are all nice and even, and your neck is accurately set up, then flat or round isn't likely to make much difference. Then again, some people seem to be into jumbo frets, or mandolin frets, so there's undoubtedly something else going on here that I don't comprehend.
But nevertheless, point one: use a magnifier or something and look at them closely. If they have obviously flattened tops, or look chewed up or uneven, then it might be time. On the other hand, if your frets don't look grossly different on the G side, then you may have a different problem...
Point two: it might be your neck setup, and not the frets. I can't quite tell how you're comparing the A/D to the E, but I could interpret you to be saying that the G is bad, A/D okay, and E great. That might suggest that the neck is slightly twisted, and you need more relief on one side than the other.
Somehow or other, I stumbled onto some
setup instructions by Gary Willis the other day (I'm not sure I even know who he is, but let that go). I'd never heard this before, but he suggested that to test your relief, just lower the bridge a little. Then,
- if you get buzz only above the 12th fret, you have too much bow.
- if you get buzz only in the first five frets, then your neck is too straight.
- if you get buzz evenly up and down the neck, then your relief is set right and you should just raise your bridge again.
(I believe that nut height also plays a role in the first few frets, but I don't think he mentions that.)
I've not yet experimented with this technique myself, but it makes some sense. In your case, it would suggest that you should tighten the truss rod on the G side a little - try an 1/8 turn tighter and see what happens.
And/or maybe just raise that side of the bridge a tweak. Might postpone a fret job, who knows. But the simple answer is, take a close look at your frets, if you want to figure out whether they're worn down, especially on one side.
-Bob