They're comfy but the sound's sparkle will be gone, soundstage will be compressed and the dynamics won't wow you after the 770.
So no, don't get them
One of the good things I can say about the Gratos is that after a pad change (vwap's pads are mandatory in my opinion), and bending the headband, they exert virtually no undesirable pressure on the ears and they're feather light compared with many phones. They're open too so you'll feel less oppressive.
For home use I think the SR80 is your ticket to something different from the DT770. I've not had the SR225 to compare but one of those could be worth looking into. Can't recommend the 325. If you're determined to waste your money go for the RS-1. Very good fun, no 'Grato', as featherlight as lesser models, but grossly overpriced for the performance. (this all assumes you don't mind a change to open phones of course!)