mind to share wat body are u using now ?
the main reason why u should move to fullframe
1. u need good wide lens, like using those high end lens for exp nikon 24-70 or 14-24 2.8 lens
2. u need to shoot high ISO most of time in darker place (events, indoor, wedding and etc)
3. u do large print, more than A4 size
4. u find that spending on those crop sensor lens are not worthy in future or not much choice of good wide lens
if those requirement meet, go for it, else, spend on lens and some good accessories go out and shoot more