The advantage was that it was fast. Other than that, there was nothing special about it.
Shen Ruyan had the Level 3 intrinsic Dharma treasure, the flying sword called the Five Lightning Immortal Slayer. Coupled with the fact that she was proficient in many lightning-element escape techniques, speed was her advantage.
Therefore, she really didn't need the Soaring Shuttle.
As for the spear, there was even less need for it because she already had the Seven Evil Treasure Spear on her.
Both of them were spear-type Dharma treasures. Shen Ruyan did not need that many at all.
On the other hand, Shen Ruyan was a little interested in the Heavenly Light Umbrella.
It was a defensive Dharma treasure.
Once it was taken out, it could produce layers of smoke-like clouds in the surroundings. It could be used for defense and concealment. It was a relatively good low-grade Level 3 defensive Dharma treasure.