It probably came with 30g weights? Since the stock grip from Scotty is probably very close to the SS slim 2.0, I would thing the 30g are fine. I have experimented with different weights in my Scotty's and honestly think it's a preference based on your swing style. Good Luck with it and welcome to the World of Scotty! :)

A 34" would come with 35g weights as the stock option. 30g is for 35". The Special Select and upcoming Super Select both come with slimmer pistolini grips, which are a bit smaller than the matadors that came on the previous 2 models. That said, I agree, there is no real formula for it. If you already had the putter and loved how it felt and then were to change grips, it may be more of a concern trying to match the same weight, but if it's a brand new putter and you only use it with the SS grip, then the stock weights are likely fine.

Welcome to the world if Scotty. I have 2. A Phantom 5.5, and a Newport 2. Both have oversize Scotty grips. The weights are all up to you and what feels the best. To me, putting is all feel. Good luck with whatever you choose. There is nothing like your first Scotty!
Play Well,
Steve S.

Weighting is definitely a feel/stroke thing that’s gonna be different for most people. Best advice is get fitted.

I have two setups I use in my Newport 2. 35g at 35” is my standard setup (considered heavy when ordering), if I know I’ll be playing on faster greens than my normal course I’ll pull the 35g weights out for 30g. Not a very big feel difference but on the same greens a 10’ putt with the 35g only goes about 9’ with the 30g. Definitely helps me not blow it by 5-6’ when the greens speed up.