It looks very nice! There won't be a discernible difference in size between this and a 1ct stone and there should be a significant savings since this is just below the carat mark!
What price is this stone? I ask because there's a beautiful BN Signature cut round for sale on Good Old Gold's web site. It's exactly the same size as the one you posted but an F in color - ie 3 grades whiter. It has all the appropriate paperwork, plus a lot more than BN offers, and is $6959 which is a great price.
Just throwing this out there in case you'd like something whiter with no chance of noticeable tint.
I hear what you're saying, JLH2016, but just so you have all the info - GOG also offers a wire price discount, and you could also get the GOG stone from BN set in any BN setting, since it's a BN stone. To me, the whiter color would be worth the extra money, but not everyone prioritizes color, so it may not be worth it to your fiancee.