I have a son at GaTech, junior if anyone has questions on that school. Familiar with Baltimore and Atlanta and both
student bodies
GaTech by state law accepts over 50% Georgia students. All valedictorians in Georgia get automatically accepted at GaTech IF their high school meets some criteria set by the Georgia Legislature.
GaTech is more fun loving student body, and less intense workload than JHU. Gatech has an excellent collaboration with Emory and a shuttle bus for BME students who want to work with medical doctors.
I would choose GaTech over JHU for the social aspects of undergraduate education.
Remember a BME undergrad is going to either get a PhD or go to medical school, so getting plenty more education at least four more years of med school or six more years of research and classes for a PhD.
The rank difference is not that big between JHU and GaTech. GaTech is arguably better for the design aspects of BME, the mechanical engineering side of BME.
Systems biology, maybe a bit better at JHU, if you are looking for research work. GaTech is particularly good at imaging sciences, tissue research, see their materials science and chemical engineering department, and of course anything related to design is superb at GaTech.
Engineering overall is better at GaTech compared to JHU if thats your bent as well.
Caltech is in a class by itself, with mathematics thats way more advanced, so a student needs to have mastered Calculus 3, and even part of differential equations to be able to earn Bs at Caltech in freshman math. It starts with Analysis. Caltech freshman have typically passed a college level physics class and that is assumed knowledge to start beginning required physics at Caltech, required for every major there.
GaTech, if you score a 7/7 on IB Physics, you can place out of freshman physics, if you want to and take a more advanced physics class, or repeat as you see fit. Physics is not the hardest class you will take at GaTech,probably, if you are taking freshman physics.
JHU and GaTech are not as challenging (ball busting???) as Caltech in physics and mathematics.