First, I apologise for bad camera shots - my only available camera is a cell phone at present.
I got in contact with Oo Jia when I saw that she was doing Milky Berry replicas; I already owned the original but I was looking to do something interesting and thus special ordered it in a colour that never originally existed - lavender!
Front: I saw no problem with the dress here; the bows are both sewn to the same standard and I found no loose threads or oddly sewn areas. Oo Jia used similar lace for each piece; the lace is all very soft. The only difference I initially noticed was that the fabric for the Angelic Pretty JSK was a tiny bit softer, though that could be from excessive wear on my end.
Back: There's a very obvious few differences here; Angelic Pretty has ties along the quarter-panel of shirring and lace along the sides, whereas Oo Jia's does not. This works for me, as I usually wear a cardigan or bolero with my dresses, but it may not be ideal for everyone. Other than that, the shirring stretch is essentially the same. I also noticed that on the inside lining of the replica, the print does not extend into the inside of the dress where it does on the Angelic Pretty JSK.
Buttons and zippers: Both buttons were similar; they are both clear and shaped like flowers. The only difference is that the Angelic Pretty buttons are shaped more like daisies, whereas Oo Jia's are shaped more like roses. Both have invisible zippers that match the dress.
EDIT: Both dresses have identical waist ties! I meant to photograph them, but forgot. I'll try to post photos later.
Print: At first, I didn't even notice it, but upon closer inspection the print on Oo Jia's is slightly larger and a mirror image. The colours are accurate to the original Angelic Pretty, and the words 'Angelic Pretty' are correctly printed, but the rest of the print is mirrored.
Lining and tulle: The tulle is slightly finer and softer in Oo Jia's version than the Angelic Pretty JSK's is, but the lining is the same and goes to what appears to be the same length under the dress.
Lace and trim: Both dresses have very soft white lace; Angelic Pretty's features strawberries whereas Oo Jia's features flowers. The biggest difference here was the size of the red ribbon in the trim. The same is true for all of the trim on the dress.
Headbows: For an extra 5 USD, you can purchase a headbow. I did for a lack of anything else the same shade of lavender in my wardrobe and was quite pleased; both headbows have the same thickness and feel. Oo Jia's is double-sided, unlike the DoL bows, and the headband can be swapped out for something different if you are so inclined. The only difference outside of the headband itself is that there is no lace on Oo Jia's.
All in all, I was very pleased with my JSK; if anyone has any questions, let me know and I'll be happy to try to answer them!