I have a few strands that are anywhere from 6-9mm, and 48 inches long, which seems to be my sweet spot length for small pearls. It's long enough to make a nice knot in, which seems to be my standard way of wearing them. I have a (7-8, I think) white 36 inch strand that kind of gets on my nerves because it seems a little too long to wear long, and likes to wrap around one boob, so I look a bit demented. It's also in my opinion a tad short for a knot.
I think 6.5-7.0mm is great for 48 inches but if it was shorter, like 36 inches, to me it would be a little insubstantial when worn doubled and I'd probably want larger pearls.
I have some PP AA+ lavender pearls that are 7-8mm. You have to inspect closely to note any off-roundness. I'm very happy with them. I think even smaller are nicer for a 48 inch strand though, the knot is smaller and of course the itty bitty ones show higher luster.
I also have a 6-7mm or so 48 inch PP white metallic strand that is considerably more off-round than the lavenders. I almost sent it back until I wore it out and by the time I returned home, I was too in love with it to return it. The off-roundness is not at all apparent when wearing them.
And I have some cheaper 48 inch Overstock ropes that are more off-round than my AA+ lavender strand, too. (The pink rope in the photo). They're not noticeably off-round when worn. Not sure if you can tell from the photos but in real life they are considerably more off-round than the PP AA+ strand.
My dyed black Overstock rope is pretty nicely round but 8-9mm. I decided it's too much pearl for me at 48 inches since I spend most of the year in shorts, so I ended up having it shortened.
So, from my point of view, rather than upgrading to AAA or getting larger pearls, I'd keep that size and grade, but increase from opera length to a 48 inch rope.
If you prefer the opera length (which I'm considering 36 inch?), then I'd upgrade the pearl size, preferably to 8 or 9mm.
But of course, just my opinion. Let us see what you get!
The doubled small white strand is AAA 7-8mm, 36 inch.
The longer black strand is Overstock (lower grade than PP AA+) 8-9mm, 48 inches.
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PP AA+ lavenders and cheaper Overstock pinks, both 7-8mm, 48 inch.
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PP AA+ lavenders, 7-8mm, up close.
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Pink Overstock pearls, two 48 inch strands
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Lavender PP 7-8mm AA+ pearls
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Off-round but AAA metallic whites, 6-7mm or so.
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