I have been looking for quite some time for a diamond for an engagement ring also. I recently went with an IGI cert diamond from Jared in Minnesota. I dont recall all of the specs, but it is a VS2, E, 1.34, deep cut by .2% (just outside of ideal I believe), very good for polish and accompanying category (cant recall), no fluor., small inclusion only seen with a scope. The cost was $9,000. I am amazed with all the bias towards the AGS/GIA cert. Every diamond that I have looked at with and AGS/GIA (cant remember) cert has been of poorer quality than the IGI I decided on. I keep hearing "our SI (AGS/GIA) is equal to other people's VS2 (IGI)" and that has not been the case. I saw an SI, 1.0k, F, most other specs were similar except good rating instead of vg. This diamond looked slightly yellow I could see inclusions without a scope. The price on this diamond was $10,000 or so. In this particular instance, in my opinion the IGI system is more reliable. I am not a gemologist by any means, but I certainly question a grading system that has people making claims that I mentioned above and then see an example that is so far off of the mark it isn't funny.