Congrats OP! These are great opportunities.
Personally, I would go with the MD Anderson program. It's a world-class research institution with so much bleeding edge research. Also, MD Anderson is very diverse. If diabetes is not your interest, you can do research in basically every body system at MD Anderson. Whether you want to do orthopaedics, endocrinology, hematology, pathology, radiology, etc., you will have the options to explore them there with some of the most renown physician-scientists. A chance to publish with them is something I would not pass up if I were you.
Also, they're being VERY generous with funding for that summer. Honestly, that would be 50% of my reason for choosing it over NIDDK.