All other things being equal, if your G1 burrs are worn either new Bunn or Ditting (Bunzilla) burrs will marginally improve your cup and make it easier to "dial" in your grind for more optimal extraction.
As the burrs break in, which really means they slowly conform to and smooth each other (look up two-piece lapping on Wikipedia) a process that probably can't be rushed in a meaningful way no matter how much rice you run through your grinder, the grind distribution will settle down and the Ditting set (in my experience) will eventually start to produce a slightly cleaner and more differentiated cup.
Burr Size: 80mm
Approximate Service Life: 15,000 lb (6800 kg)
Available on backorder
If you are producing a lot of dark roast coffee, there probably isn’t a heck of a lot of difference. If you are producing specialty, light-roast coffee where your goal is a cleaner and more differentiated cup, the slightly superior grind quality of the Ditting will help to accentuate those qualities.
Edit: For the record. I used an old G1 with Ditting burrs and Trifecta parts (for finer adjustment points) as a cupping grinder for a couple of years before picking up a used Ditting 804. The 804 was another slight bump in grind quality up from the Bunzilla. Last year, I bit the bullet, sacrificed $2500 for a new 804 lab grinder, and fell in love. Impossible to beat for the money and size. It cups equal to (IMO) an EK-43 in a smaller and quieter package.
Free advice: start with what you can afford relative to what you can taste. If you’re Q-certified, you’ll probably want top-quality gear. If you’re still discovering your palate, start where the money makes sense and grow from there.