I love these so much, I'm about to purchase my third pair! I've owned several real Valentino sandals/flats and these dupes, while not perfect, are very similar. What makes them great is the quality materials and craftsmanship. There are no super obvious construction flaws, such as bad stitching or noticeable glue marks. If you want to be hyper-critical, I'm sure you could find "red flags," but how many people are going to get close to your feet and inspect them?
If I had to point out a potential flaw that you might find, I would say that sometimes a stud may be slightly off--either turned a bit or not centered between its neighboring studs. I am returning a pair that had this flaw, which I just noticed after having it for a few weeks. My other pair is absolutely perfect.
Regarding fit, I'd compare it to real Valentino sizing, which is about a half-size small. I normally wear a size 8 in flats and sandals, but in both the real Valentino flats and the Kaitlyn Pan version, I wear an 8.5/38.5. I just purchased and returned another real rockstud ballet flat (the new one with black studs) because the fit was really weird and I liked how the KP-version of the ballet flat fit much better!