With the V5 having many reported issues, I had high expectations for the TWO pairs of v5.1 I ordered. (One was for my GF, will test the QC) I had previously owned a pair of v4.9 TB's, so I will be comparing those two, as it seems that there are a lot of people asking the differences.
First off, packaging was great, came in the standered "generic" earbud box, followed by the actual box, the plastic wrapper felt very high quality and apple-ish with the pull tabs ofc, box's font and coloring looked on point as well. 10/10
Sound quality: 10/10 Bass seamed to be the exact same on both pairs, compared to the v4.9 TB's, it seemed a bit heavier, even though ive seen people quoting jenny as saying that the v4.9 TB's where bass heavier.
ANC: 9.5/10 No "fuzzy white noise" or anything like that, very clear, could not hear anything. I own a pair of sony WH-1000XM4 headphones as well, and even though this is an unfair comparison, I prefer the airpods in terms of ANC and sound quality.
Transparency: 9.8/10 Amazing, it felt like a speaker out in the open, but did not hinder sound quality. Very good, and was identical on both pairs of the v5.1's I bought.
Build quality: 10/10 Not much to say here, felt very sturdy, no issues at all. Case hinge felt identical compared to a friends genuine airpods pro 2nd gen, case also had some good weight to it, making it even closer to the identical version.
Shipping: These came pretty damn fast, I bought on the day these dropped, I do live in the EU though. So it took 7 days!!!
Battery life: 10/10 tested by playing AJR's OK orchestra on medium volume. Lasted ~7H.
THE TWO MOST COMMON QUESTIONS SURROUNDING THE V5.1'S
QC - The two pairs I bought, where identical in every way, I dont know what else to say, they were the exact same. I understand some pairs of the v5 had some issues off the bat, but jenny likely fixed them with the v5.1. (At least in my experience)
V5.1 VS 4.9 TB - PICK THE V5.1!!!!!!! BETTER IN EVERY WAY!

glad u enjoy it