It is probably like pounds vs kilograms… whatever you are used to will be easiest for you.
I like the way I describe percentages for three main reasons (other than my personal view of the aesthetics of having different percentages depending on starter vs. instant yeast):
- It shows you very clearly the hydration percentage.
- No guesswork on the hydration level of the starter. I assume your recipe uses 100% hydration starter, but your ratios do not confirm this unless you read the description of how you calculate the formulas. Most recipes will not include the textual description of how to amounts/percentages were determined.
- The percentages for salt and other ingredients never change and are easy to calculate (i.e., salt divided by flour rather than salt divided by (flour + half of starter)). For example, I use 2% salt as a standard ratio and can evaluate all recipes against this. I think having a single universal percentage for all items has great value for non-experts like me.