If you manage to stomach it and continue, you will get two huge boosts that will sustain your interest temporarily. When you shift from T2 to T3, sacred items will start dropping and even the blues will be better than your current equipment - kinda like the feeling when EQ or WoW would launch an expansion. You will find plenty of upgrades, but then you will hit the wall again until you get into T4, and then ancestral items will drop, replacing your sacred items, and for a short while you will have a sense of progress as you replace all your gear.
After that, it's a slog. Minimal chances of upgrades, and you will be running the same content over and over again.
Season 1 is around the corner, not sure if you and the wife will have any interest in that. If so, you can shelve your current characters and start anew, since the 1-60 game is funner than the 60-100 game imo.