If I remember correctly, I got the decision email last year on a Monday night/Tuesdsay morning (April 2/3, 2018)
I think the positive feedback from those in your field is a good sign. Keep in mind that these applications are (afaik) reviewed by people in the general field you applied for, so I think jargon is expected. I think some of the feedback I received last year was fairly technical.
I know the long wait for results leads to a lot of anxiety and time to have doubts, however unfounded they are. I didn't get the GRFP the first time around and it was frustrating, but in hindsight it taught me a lot about writing proposals and things worked out in the end. For many of us, this is our first experience writing a research proposal. These uncharted waters lead to a lot of stress, so take a deep breath and know that there are many others in the same position.