as a bit of a PSA, sorry if this was something you were already aware of:
graceful boosts energy restoration when walking or standing still. So to get value from it you have to actively be not running, which is bad.
The weight reduction is still good, but other items are easier to obtain and give more weight reduction, also if you're below 0kg it has no further impact.
There are a lot of situations where people like graceful but actually it's bad or at least not useful. Energy potions and ferox pool are typically better as well as more accessible because they let you keep running rather than walking. In addition, they don't require a 15hr+ grind to obtain.
All things considered I'd say graceful is somewhat niche, and a very low priority. If you want it go for it, but you are never recouping those hours spent at a low tier rooftop course.