Stick with the default spring weight, I know the G29/30/36 are 17lbs.
I was just looking at the tungsten RSA today for my G30. It's a crazy $70! However, I was at the range on Monday practicing my double-tap and realized just how much flip I was getting on my 2nd round, as well as loss of accuracy.
If I get the tungsten, I'll get it for the reduced flip but I'll keep the same spring weight.
My stock RSA broke and I replaced it with stock and thought it works fine, but that was because I was only firing one round at a time at a target and accuracy was acceptable.
I forgot to ask if it is a Gen 4, if so, you already have the heavier spring. I have not tried this in a G23, but I have talked to people that claimed to have the 20lb spring in theirs and they swear by it. The 17lb should be stock size. Glockstore.com has the kits with the SS rods and captured springs, I would recommend this type. The difference is the guide rod has a retaining clip on the end the keeps the spring from flying off.
If you have the money, I would starting with the 17 and move up, then sell the ones you don't need.
Is it better, depends on who ya ask. I was a 1911 guy forever and felt it was an upgrade. Lone Wolf 17lb ss guide rod was what I installed in my G17...never an issue and suggests it to everyone locally!