Tell them you want to see the actual GIA report before you make any decisions. Not just the report number. The whole thing. If they don't give you a copy of it or let you take a photo of it, you need to rethink this. You want the plot, and the angles.
The WHOLE thing. An I1 gives me pause, but if it's well cut and the inclusion isn't bothersome, that's fine. But since you can get a stone around that size of those specs (I1 specifically) for just barely more than that without even trading in...I feel this isn't a worthy trade.
Regarding the comment about how this one looked better than the VS1 you looked at--
Looked better how? In general terms of the clarity? Or as a whole with sparkle, light return, etc? Because if it's cut better that's why it might have looked better.
In regards to the I1 stone: Could you see the inclusion with your naked eye? Did you see it in any other lighting besides just the blinding store lights? Like by a window? You need to see it in other conditions to know how this inclusion will affect your eyes in daily life. To see if you can live with it.
So with this stone, you're in with Jared for $4300
plus whatever you paid right? What was the price difference between the VS1 and the I1 in terms of financial outlay (including trade obviously)? You can PM me that if you want, but that's important to know. What is the max you are willing to spend on this upgrade (outside of trade, obviously). Because your threshold on that is also important. And another thing--can you upgrade through Kay/Jared again if you decide this stone isn't acceptable later? Or you want larger? What's the return options if you start to "See" the inclusion?
Just for reference: a well cut diamond in that range with a reputable lab report (GIA or AGS) should run you around 5000-6500 without a trade in, depending on vendor. You might be better off going elsewhere and buying a whole new ring for your money and keeping this one for sentimental value.
So based on that thought process, that you're about to trade in your ring, plus shell out upwards of $4500 to even $7000 more ...I did a rudimentary look for stones in that size and color/clarity range (though I'd probably avoid buying from a vendor without good images in this clarity range) brings these up, worth considering if you're already looking at spending a decent chunk of change to see what you can get with the money and not even trade your current one in.
(its a J, and a nice J)
http://goodoldgold.com/diamond/12120/
(larger table than I typically recommend, but has a nice ASET and idealscope)
http://goodoldgold.com/diamond/12369/
These should all be beautifully cut, but you'd need some images sent from Blue Nile to see about whether these inclusions are acceptable.
http://www.bluenile.com/diamond-details/LD04457133
http://www.bluenile.com/diamond-details/LD04760791
http://www.bluenile.com/diamond-details/LD04670607
http://www.bluenile.com/diamond-details/LD04646324
These have images for you to view:
http://www.jamesallen.com/loose-dia...arat-j-color-si1-clarity-ideal-cut-sku-362325
http://www.jamesallen.com/loose-dia...-j-color-si1-clarity-excellent-cut-sku-322407
http://www.jamesallen.com/loose-dia...-i-color-si1-clarity-excellent-cut-sku-347411
Need to make sure they're eyeclean:
http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3063753.htm
http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3157625.htm
http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3178634.htm
http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3192755.htm
higher end of the cost spectrum and slightly larger table than I otherwise go to but worth a look
http://www.briangavindiamonds.com/d...ls/1.237-i-si1-round-diamond-ags-104064813021
smaller than you were looking at, worth a look
http://www.briangavindiamonds.com/d...1.023-i-si1-round-diamond-ags-bl-104070945011