So, I recently went through the process of ordering and receiving a downpipe. Haven't yet installed - I got side tracked with oil pan, etc. Anyhow, you may have already found this out yourself but it is currently very hard to find an Invidia in stock. I called a few places that claimed (or at least appeared) to have it in stock or soon to ship online. All of them were backordered, months. One place (autocity imports) was very curious to see if I could find it anywhere.
I ended up going COBB just because of availability. It is more expensive, and I am not sure if it's any better or worse. One VERY interesting thing though regarding the COBB - The catalytic converter shown in the picture on their website shows an EPA certified model from GSPORT. Based on claimed specs, I believe it would be PN50030 at link below:
https://gsportbygesi.com/high-performance-catalytic-converters/g-sport-emissions-systems-products/
When I received the COBB downpipe I was pretty angry/disappointed to find the cat welded into the pipe was not the one shown in the pics. I was really hoping for at least an EPA cert ... could make convincing a mechanic to give me inspection a bit easier. It appears to be a non-certified model.
HOWEVER !! - and this is a big however, I talked to COBB customer service because I felt done wrong. Was happy to find out the rep was really knowledgeable on the subject. He says the model I received is in fact not EPA cert, but it is a new part they jointly developed with GSPORT that they soon hope to have full CARB cert on! Man, if they achieve this I will be happy as a clam. Claimed time from to cert could be "months".
Long story short - I am happy with my COBB even if it was a bit more than Invidia, I think.