I ordered a set of 2.5" and 3" Alibaba Z1 replica intakes as part of my bigger intake comparison.

Youtube video here:

Differences:
1. The Alibaba piping isn't perfectly round. There's imperfections in the shape.
2. MAF mounting block on the Alibaba intakes are tall, placing the MAF sensor further up in the pipe while the Z1 places it in the center.
3. The 2.5" piping is shorter, can possibly cause fitment issues.

Price wise, the Alibaba intakes costed $200 each shipped to my door. For the cheap price, its expected for these imperfections.

Here are some pictures next to the Z1 Motorsports intakes


Filters for 3"

Filters for 2.5"

2.5" piping

2.5" piping

2.5" piping

2.5" piping

2.5" piping

3" piping

3" piping