Hi there!

I also read through all the posts!
From the list from JP, I would say the 0.51 G VS2 is the best buy! but it would bust your budget by $250. Do you think it's worth it? The next best is 0.43 E VVS2 but I feel top wise can tell the slight size difference. However, if you're not getting the 0.51 due to budget constraints and no time to wait for next shipment (which I have no idea when), I would propose asking for ideal cuts so you could hit the 0.5 CT weight. Do caution though that for the ideal cuts, you really have to look through the scopes carefully cuz their range of quality quite big x.x
For Poh Kim, I would avoid 0.55. Actually if you're at such shops, should ask if you're able to view the diamonds under natural lighting so u could compare.. Especially when they don't provide ASET scope to view the diamond. Another alternative (if I'm not wrong) is taking a piece of paper and just have some scribble lines and see if they allow u to put the diamond there to turn turn around different angles to check for light leakage (cuz light leakage would mean u can see through the diamond and see ur scribble lines).
As for the hearts, is it just me? I've seen quite a few relatively symmetrical hearts and arrows but what bugs me are the cracks of the heart (top middle). Not that obvious but once I see them I can't unseen them.. I believe they affect something too right? Could someone please enlighten me?
Anyway, as a lady, I really don't want a dull-looking ring. It doesn't have to be "perfect" but if you're getting a diamond, then it better bling well. And I always feel, half carat is a sweet spot haha..
But in all honesty, really depends on your tolerance level and how particular your partner is