You need to realize none of these strollers are very sturdy / durable. For the price and size, they are ok for undemanding, ideally occasional use, but that durability comes at a higher weight and larger size, or a higher price tag (for the sturdiest option at. that size, check the Joolz Aer+.
Out of the two, I personally would go for the GB. It is so because of the size, which is smaller when folded, so more suitable for plane travel. The seat feels more comfy, sitting wise, from my point of view, but the Parcel has it nicely padded, which is a nice thing to have.
In general, the GB feels more practical for me, but again, I have to underline sturdiness and durability aren't the strong sides of either of them.