I always find these discussions fascinating. Real vs Fake vs Counterfeit.

The motive and intent behind such purchases becomes crucial. Strictly as an experiment or test case I can understand the rationale. Sometimes we subconsciously look to the forums for validation to justify our purchases. The overwhelming number of replies I've seen in here over the years point to fake/counterfeit frames being a bad idea for the variety of aforementioned reasons.

So ultimately it comes down to what purpose a fake frame will serve. Your money your choice end of the day.

For context, I looked into getting a counterfeit Rolex Submariner over 3 years ago. Even back then the VSF Chinese factories practically perfected the Submariner. I can't imagine what tiny nuances they've improved on these days. But in the end I settled on a super high quality homage watch. Almost identical specs as the Rolex, and comes with a warranty. The brand isn't trying to pass their watch off as Submariner which I appreciate.

The irony here is the fake frame and fake Rolex both could pose injury to the owner. If you know what I mean...

Saying that "counterfeiting is OK because the brands would otherwise rip me off" is ridiculous. To me, it's more like "fake=bad, real=?"

i disagree with the customer groups.

I think the lines are much more blurred than real vs fake. What about that whole grey area of frames that are basically almost a replica except for minor details? How many almost clones of the SL7 are out there? The Trifox X18, the VB-R168 and so on.
The ICAN A22 which is basically a Canyon Aeroad. The TanTan X34 which is made to look like a Madone. The X38 which is basically a Scott Foil except for the headset, bars and seatpost. The list goes on.

Also, many of these - despite having minor differences in appearance to the original - have basically the same geometry as the models they took "inspiration" from. So I'm not sure how much R&D actually went into these designs.

Personally, I think were not even talking remotely about the same customer groups. Somebody who actually has the cash to pay 4-6000USD for a frameset or a five digit number for a bike would never think about getting a 5-800 dollar chiner frame.
Making the fake look like the real one with logos and so on is where I definitely draw the line. Especially when those frames then flood the 2nd hand market. There's so many Pinarello clones with logos and paintjobs like the originals that I'd worry if I could actually tell the difference if I ever bought a 2nd hand frame.

Where I take umbrage is in the steep barrier to entry when it comes to cycling, and 'the scene'.

But I don't begrudge anyone who doesn't have the means, to want to build up an expensive replica knowing the potential headaches they'll face when building and riding it.

2. Is replica going to be as good as the real thing performance wise?

Absolutely not, but is it close? I would say yes, replica tends to feel less stiff, a bit heavier and a little bit sluggish. If I really need to give a direct comparison, I will say replica has 90% of the performance, in fact, we all sort of know the answer, if you get dropped, problem's on you, not the bike. Honestly if you are not a racer, don't bother, I don't really think a racer would consider buying replica anyway.