The huge advantage to a ground blind in my experience and opinion is you can't fall out of it and seriously injure yourself. I have had a few close calls over the years in tree stands and a close friend 4 yrs. ago fell 15ft. while taking one down and broke his back. Freak accident, chain broke. Paralyzed from the waist down which includes the private parts and bits. His hunting days ended with that fall.
Also something to consider I guess. Not a fan of heights anyways and tree stands seem pretty rickety.