I have a rebel APS-C body 550d. I added a grip. It is light, inexpensive, easy to use, and fits my needs as a hobby photographer as well.
For me and my hobby, the experience of getting the shot is the priority. I use primes, and get to use the sweet spot of the lens. I have a 35L, 50 1.4, and samyang 85 1.4 MF. The MF is a challenge to use, but fun and rewarding. For WA I use the samyang 14mm 2.8 MF (excellent lens).
I have spent much time comparing FF images with crop images online. True, for professional work, especially high end photography, you would need a FF, however you would also need, lighting, studio, props, and all the other equipment a pro works with to take advantage of the FF abilities. For what I do, the heavy/expensive FF, would not make my hobby more pleasant. I am also not sure my general street shots / home portraits would be substantially better.
So for me, the question "is it worth it" - is totally subjective, depending on my needs, and financial abilities. For me the answer right now is no.